485BPOS

As filed with the U.S. Securities and Exchange Commission on November 13, 2018

File No. 033-47287

File No. 811-06637

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C.  20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933	x
Pre-Effective Amendment No.	o
Post-Effective Amendment No. 136	x

and/or

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940	x
Amendment No. 137

(Check appropriate box or boxes.)

THE UBS FUNDS

(Exact Name of Registrant as Specified in Charter)

One North Wacker, Chicago, Illinois  60606

(Address of Principal Executive Office)  (Zip Code)

Registrant’s Telephone Number, including Area Code  312-525-7100

Mark F. Kemper

UBS Asset Management (Americas) Inc.

One North Wacker

Chicago, Illinois  60606

(Name and Address of Agent for Service)

Please send copies of all communications to:

Bruce G. Leto, Esq.

Stradley Ronon Stevens & Young, LLP

2005 Market Street, Suite 2600

Philadelphia, PA 19103

(215) 564-8027

Approximate Date of Proposed Public Offering: As soon as practicable after the effective date of this registration statement.

It is proposed that this filing will become effective (check appropriate box):

x  immediately upon filing pursuant to paragraph (b)

o  on [Date] pursuant to paragraph (b)

o  60 days after filing pursuant to paragraph (a)(1)

o  on [Date] pursuant to paragraph (a)(1)

o  75 days after filing pursuant to paragraph (a)(2)

o  on [Date] pursuant to paragraph (a)(2) of Rule 485.

If appropriate, check the following box:

o  This post-effective amendment designates a new effective date for a previously filed post-effective amendment.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended (the “Securities Act”) and the Investment Company Act of 1940, as amended, the Registrant certifies that it meets all of the requirements for effectiveness of this Registration Statement under Rule 485(b) under the Securities Act and has duly caused Post-Effective Amendment Nos. 136/137 to this Registration Statement on Form N-1A to be signed on its behalf by the undersigned, duly authorized, in the City of New York, and the State of New York on the 13th day of November, 2018.

THE UBS FUNDS
By:	/s/ Igor Lasun
	Igor Lasun*
	President and Principal Executive Officer

Pursuant to the requirements of the Securities Act, this Registration Statement has been signed below by the following persons in the capacities and on the dates indicated:

Signature	Title	Date
/s/ Igor Lasun	President and Principal Executive Officer	November 13, 2018
Igor Lasun *
/s/ Frank K. Reilly	Chairman and Trustee	November 13, 2018
Frank K. Reilly*
/s/ Joanne M. Kilkeary	Principal Accounting Officer and Treasurer	November 13, 2018
Joanne M. Kilkeary*
/s/ Adela Cepeda	Trustee	November 13, 2018
Adela Cepeda*
/s/ J. Mikesell Thomas	Trustee	November 13, 2018
J. Mikesell Thomas*
/s/ Abbie J. Smith	Trustee	November 13, 2018
Abbie J. Smith*
/s/ John J. Murphy	Trustee	November 13, 2018
John J. Murphy*

* By:	/s/ Keith A. Weller
	Keith A. Weller, Attorney-in-Fact
	(Pursuant to Powers of Attorney, incorporated herein by reference)

2

EXHIBIT INDEX

Index No.	Description of Exhibit
EX-101.INS	XBRL Instance Document
EX-101.SCH	XBRL Taxonomy Extension Schema Document
EX-101.CAL	XBRL Taxonomy Extension Calculation Linkbase
EX-101.DEF	XBRL Taxonomy Extension Definition Linkbase
EX-101.LAB	XBRL Taxonomy Extension Labels Linkbase
EX-101.PRE	XBRL Taxonomy Extension Presentation Linkbase

XML

Document and Entity Information	Total
Prospectus:
Document Type	485BPOS
Document Period End Date	Jun. 30, 2018
Registrant Name	UBS FUNDS
Central Index Key	0000886244
Amendment Flag	false
Document Creation Date	Oct. 23, 2018
Document Effective Date	Oct. 23, 2018
Prospectus Date	Oct. 23, 2018
UBS Engage For Impact Fund | Class P
Prospectus:
Trading Symbol	UEIPX
UBS Engage For Impact Fund | Class A
Prospectus:
Trading Symbol	UEIAX
Class A and P Prospectus | UBS Sustainable Development Bank Bond Fund | Class P
Prospectus:
Trading Symbol	UDBPX
Class A and P Prospectus | UBS Sustainable Development Bank Bond Fund | Class A
Prospectus:
Trading Symbol	UDBAX
Class P2 Prospectus | UBS Sustainable Development Bank Bond Fund | Class P2
Prospectus:
Trading Symbol	UDBTX

XML

UBS Engage For Impact Fund

UBS Engage For Impact Fund

Investment objective

The Fund seeks to maximize total return, consisting of capital appreciation and current income.

Fees and expenses

These tables describe the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for a sales charge waiver or discount if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund. More information about these and other discounts and waivers, as well as eligibility requirements for each share class, is available from your financial advisor and in "Managing your fund account" beginning on page 20 of this prospectus and in "Reduced sales charges, additional purchase, exchange and redemption information and other services" beginning on page 62 of the Fund's statement of additional information ("SAI").

Different intermediaries and financial professionals may make available different sales charge waivers or discounts. These variations are described in Appendix A beginning on page A-1 of this prospectus.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees - UBS Engage For Impact Fund	Class A		Class P
Maximum front-end sales charge (load) imposed on purchases (as a % of offering price)	5.50%		none
Maximum contingent deferred sales charge (load) (CDSC) (as a % of purchase or sales price, whichever is less)	none	[1]	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses - UBS Engage For Impact Fund		Class A	Class P
Management fees		0.75%	0.75%
Distribution and/or service (12b-1) fees		0.25%	none
Other expenses	[1]	0.44%	0.44%
Total annual fund operating expenses		1.44%	1.19%
Less management fee waiver/expense reimbursements	[2]	0.34%	0.34%
Total annual fund operating expenses after management fee waiver/expense reimbursements	[2]	1.10%	0.85%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods unless otherwise stated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The costs described in the example reflect the expenses of the Fund that would result from the contractual fee waiver and expense reimbursement agreement with the Advisor for the first year only. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Expense Example - UBS Engage For Impact Fund - USD ($)	1 year	3 years
Class A	656	949
Class P	87	344

Portfolio turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. Because the Fund had not yet commenced operations as of the date of this prospectus, it does not have a portfolio turnover rate to provide.

Principal strategies

Principal investments

To achieve its investment objective, the Fund invests in, or seeks exposure to companies based on various financial factors, fundamental sustainability factors such as environmental, social and governance performance along with assessing the current and potential ability of such companies to have a measurable impact on society and the environment.

Under normal circumstances, the Fund invests a substantial portion of its net assets (plus borrowings for investment purposes, if any) in equity securities. Investments in equity securities may include, but are not limited to, dividend-paying securities, common stock and preferred stock of issuers located throughout the world; Global, European and American Depositary Receipts; as well as investment companies, including exchange-traded funds ("ETFs"). The Fund may invest in issuers from both developed markets (including the United States) and emerging markets. The Advisor, on behalf of the Fund, intends to diversify broadly among countries, but reserves the right to invest a substantial portion of the Fund's assets in one or more countries if economic and business conditions warrant such investments. The Fund may invest in stocks of companies of any size.

The Fund may, but is not required to, use exchange traded or over-the-counter ("OTC") derivative instruments for risk management purposes or as part of the Fund's investment strategies. Generally, derivatives are financial contracts whose value depends upon, or is derived from, the value of an underlying asset, reference rate, index or other market factor and may relate to stocks, bonds, interest rates, credit, currencies or currency exchange rates, commodities and related indexes. The derivatives in which the Fund may invest include futures, forward currency agreements and equity participation notes. All of these derivatives may be used for risk management purposes to manage or adjust the risk profile of the Fund. Futures on currencies and forward currency agreements may also be used to hedge against a specific currency. In addition, all of the derivative instruments listed above may be used for investment (non-hedging) purposes to earn income; to enhance returns; to replace more traditional direct investments (except for forward currency agreements); or to obtain exposure to certain markets (except for forward currency agreements). The Fund also may use futures contracts on equity securities and indices to gain market exposure on its uninvested cash.

Management process

The Advisor seeks to invest in companies that the Advisor believes are attractively valued, that integrate sustainability factors into the business model to build a competitive advantage, whose products and services can create meaningful, intentional, verifiable and measurable impact on society and the environment; and which have a clearly identified potential for additional positive impact that the Advisor intends to drive through engagement with the companies. In selecting individual securities for investment, the Advisor considers, among other factors:

•  Its assessment of fundamental valuation (price/intrinsic value) to seek attractively valued companies with strong financial performance;

•  Quantitative and qualitative environmental, social and governance ("ESG") factors;

•  Quantitative and qualitative assessment of a company's current and potential impact on society and the environment; and

•  Advisor's ability to drive positive change in a company's impact profile through engagement.

The Advisor aims to identify the best investment ideas with additional impact potential across the market capitalization spectrum, sectors and geographies within the eligible investment universe ("the impact universe").

The impact universe is comprised of companies whose products and services can create measurable, verifiable impact within specific impact categories (such as climate change, air pollution, clean water and water scarcity, treatment of disease and food security and others) that are aligned with the United Nations Sustainable Development Goals. The Advisor's assessment of the ability of public companies to generate impact is based upon impact measurement methodologies the Advisor has developed in partnership with academics from the fields of earth sciences and public health science. The impact of portfolio holdings is measured in changes in human well-being and changes in environmental quality (e.g. reduction in air pollution, hospitalizations and biodiversity loss).

Engagement with portfolio companies is a key aspect of the Fund's strategy. Companies have the potential to create additional impact through improving or optimizing the use of their products and services throughout society as well as indirectly through changes to their operations and supply chain. The Advisor's Global Sustainable Equities team and the Sustainable Research staff will seek to increase impact at each portfolio company through engagement on both fronts through communication with company management and continuous monitoring of the company's ESG impact. The Advisor will establish specific impact goals, and measure and evaluate progress regularly in order to assess the impact of its engagement efforts. The purpose of engagement with companies is to:

•  Improve the Advisor's ability to independently measure impact;

•  Engage the company to help it inform its strategy with regard to societal goals;

•  Engage the company to help increase its product and service impact by identifying target markets, customers and business partners that create additional impact over time; and

•  Engage the company to identify business model risks and opportunities linked to the ESG component of operations, supply chains and other aspects of the company that can help increase positive impact over time.

The Advisor will employ both a positive and negative screening process with regard to securities selection for the Fund. The negative screening process will exclude securities of companies with more than 5% of sales in alcohol, tobacco, defense, nuclear, gambling and pornography from the Fund's portfolio. The Advisor may modify this list of negative screens at any time, without shareholder approval or notice. The positive screening process seeks to identify securities of companies that provide solutions to significant global challenges through the impact of their products and services, that are attractive based on their fundamental and valuation profile in addition to evaluating specific sustainability (ESG) factors as well as the ability of the Advisor to engage with the company's management on impact-related issues.

Main risks

All investments carry a certain amount of risk, and the Fund cannot guarantee that it will achieve its investment objective. You may lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Below are some of the specific risks of investing in the Fund.

Derivatives risk: The value of "derivatives"—so called because their value "derives" from the value of an underlying asset, reference rate or index—may rise or fall more rapidly than other investments. It is possible for the Fund to lose more than the amount it invested in the derivative. The risks of investing in derivative instruments also include market risk, management risk, counterparty risk (which is the risk that a counterparty to a derivative contract is unable or unwilling to meet its financial obligations) and the risk that changes in the value of a derivative may not correlate perfectly with the underlying asset, rate, index or overall market securities. In addition, non-exchange traded derivatives may be subject to liquidity risk, credit risk and mispricing or valuation complexity. These derivatives risks are different from, and may be greater than, the risks associated with investing directly in securities and other instruments.

Emerging market risk: There are additional risks inherent in investing in less developed countries that are applicable to the Fund. Compared to the United States and other developed countries, investments in emerging market issuers may decline in value because of unfavorable foreign government actions, greater risks of political instability or the absence of accurate information about emerging market issuers. Further, emerging countries may have economies based on only a few industries and securities markets that trade only a small number of securities and employ settlement procedures different from those used in the United States. Prices on these exchanges tend to be volatile and, in the past, securities in these countries have offered greater potential for gain (as well as loss) than securities of companies located in developed countries. Further, investments by foreign investors are subject to a variety of restrictions in many emerging countries. Countries such as those in which the Fund may invest may experience, high rates of inflation, high interest rates, exchange rate fluctuations or currency depreciation, large amounts of external debt, balance of payments and trade difficulties and extreme poverty and unemployment.

Foreign investing risk: The value of the Fund's investments in foreign securities may fall due to adverse political, social and economic developments abroad and due to decreases in foreign currency values relative to the US dollar. Investments in foreign government bonds involve special risks because the Fund may have limited legal recourse in the event of default. Also, foreign securities are sometimes less liquid and more difficult to sell and to value than securities of US issuers. These risks are greater for investments in emerging market issuers.

Geographic concentration risk: The risk that if the Fund has most of its investments in a single country or region, its portfolio will be more susceptible to factors adversely affecting issuers located in that country or region than would a more geographically diverse portfolio of securities.

Investing in ETFs risk: The Fund's investment in ETFs may subject the Fund to additional risks than if the Fund would have invested directly in the ETF's underlying securities. These risks include the possibility that an ETF may experience a lack of liquidity that can result in greater volatility than its underlying securities; an ETF may trade at a premium or discount to its net asset value; or an ETF may not replicate exactly the performance of the benchmark index it seeks to track. In addition, investing in an ETF may also be more costly than if a Fund had owned the underlying securities directly. The Fund, and indirectly, shareholders of the Fund, bear a proportionate share of the ETF's expenses, which include management and advisory fees and other expenses. In addition, the Fund will pay brokerage commissions in connection with the purchase and sale.

Leverage risk associated with financial instruments: The use of financial instruments to increase potential returns, including derivatives used for investment (non-hedging) purposes, may cause the Fund to be more volatile than if it had not been leveraged. The use of leverage may also accelerate the velocity of losses and can result in losses to the Fund that exceed the amount originally invested.

Management risk: The risk that the investment strategies, techniques and risk analyses employed by the Advisor may not produce the desired results.

Market risk: The market value of the Fund's investments may fluctuate, sometimes rapidly or unpredictably, as the stock and bond markets fluctuate. Market risk may affect a single issuer, industry, or sector of the economy, or it may affect the market as a whole.

Small- and mid-capitalization risk: The risk that securities of smaller capitalization companies tend to be more volatile and less liquid than securities of larger capitalization companies. This can have a disproportionate effect on the market price of smaller capitalization companies and affect the Fund's ability to purchase or sell these securities. In general, smaller capitalization companies are more vulnerable than larger companies to adverse business or economic developments and they may have more limited resources.

Sustainability factor risk and risk of impact investing: The Fund's sustainability factors used in its investment process and the Advisor's impact investing approach will likely make the Fund perform differently from a fund that relies solely or primarily on financial metrics. The sustainability factors and the Advisor's impact investing approach may cause the Fund's industry allocation to deviate from that of funds without these considerations.

Performance

There is no performance information quoted for the Fund as the Fund had not commenced investment operations as of the date of this prospectus.

[1] Purchases of $1 million or more that were not subject to a front-end sales charge are subject to a 1% CDSC if sold within one year of the purchase date.

[1] "Other expenses" are based on estimates for the current fiscal year.

[2] The Trust, with respect to the Fund, and UBS Asset Management (Americas) Inc., the Fund's investment advisor and administrator ("UBS AM (Americas)" or the "Advisor"), have entered into a written agreement pursuant to which the Advisor has agreed to waive a portion of its management fees and/or to reimburse expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions and extraordinary expenses) to the extent necessary so that the Fund's ordinary operating expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions and extraordinary expenses), through the period ending October 29, 2019, do not exceed 1.10% for Class A shares and 0.85% for Class P shares. Pursuant to the written agreement, the Advisor is entitled to be reimbursed for any fees it waives and expenses it reimburses to the extent such reimbursement can be made during the three fiscal years following the date on which such fee waivers and expense reimbursements were made, provided that the reimbursement of the Advisor by the Fund will not cause the Fund to exceed the lesser of any applicable expense limit that is in place for the Fund (i) at the time of the waiver or reimbursement or (ii) at the time of the recoupment. The fee waiver/expense reimbursement agreement may be terminated by the Fund's Board of Trustees at any time and also will terminate automatically upon the expiration or termination of the Fund's advisory contract with the Advisor. Upon termination of the fee waiver/expense reimbursement agreement, however, UBS AM (Americas)'s three year recoupment rights will survive.

XML

Label

Element

Value

UBS Engage For Impact Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

UBS Engage For Impact Fund

Objective [Heading]

rr_ObjectiveHeading

Investment objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks to maximize total return, consisting of capital appreciation and current income.

Expense [Heading]

rr_ExpenseHeading

Fees and expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

These tables describe the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for a sales charge waiver or discount if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund. More information about these and other discounts and waivers, as well as eligibility requirements for each share class, is available from your financial advisor and in "Managing your fund account" beginning on page 20 of this prospectus and in "Reduced sales charges, additional purchase, exchange and redemption information and other services" beginning on page 62 of the Fund's statement of additional information ("SAI").

Different intermediaries and financial professionals may make available different sales charge waivers or discounts. These variations are described in Appendix A beginning on page A-1 of this prospectus.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

Oct. 29, 2019

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. Because the Fund had not yet commenced operations as of the date of this prospectus, it does not have a portfolio turnover rate to provide.

Expense Breakpoint Discounts [Text]

rr_ExpenseBreakpointDiscounts

You may qualify for a sales charge waiver or discount if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund.

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

$ 50,000

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

"Other expenses" are based on estimates for the current fiscal year.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods unless otherwise stated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The costs described in the example reflect the expenses of the Fund that would result from the contractual fee waiver and expense reimbursement agreement with the Advisor for the first year only. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Principal investments

To achieve its investment objective, the Fund invests in, or seeks exposure to companies based on various financial factors, fundamental sustainability factors such as environmental, social and governance performance along with assessing the current and potential ability of such companies to have a measurable impact on society and the environment.

Under normal circumstances, the Fund invests a substantial portion of its net assets (plus borrowings for investment purposes, if any) in equity securities. Investments in equity securities may include, but are not limited to, dividend-paying securities, common stock and preferred stock of issuers located throughout the world; Global, European and American Depositary Receipts; as well as investment companies, including exchange-traded funds ("ETFs"). The Fund may invest in issuers from both developed markets (including the United States) and emerging markets. The Advisor, on behalf of the Fund, intends to diversify broadly among countries, but reserves the right to invest a substantial portion of the Fund's assets in one or more countries if economic and business conditions warrant such investments. The Fund may invest in stocks of companies of any size.

The Fund may, but is not required to, use exchange traded or over-the-counter ("OTC") derivative instruments for risk management purposes or as part of the Fund's investment strategies. Generally, derivatives are financial contracts whose value depends upon, or is derived from, the value of an underlying asset, reference rate, index or other market factor and may relate to stocks, bonds, interest rates, credit, currencies or currency exchange rates, commodities and related indexes. The derivatives in which the Fund may invest include futures, forward currency agreements and equity participation notes. All of these derivatives may be used for risk management purposes to manage or adjust the risk profile of the Fund. Futures on currencies and forward currency agreements may also be used to hedge against a specific currency. In addition, all of the derivative instruments listed above may be used for investment (non-hedging) purposes to earn income; to enhance returns; to replace more traditional direct investments (except for forward currency agreements); or to obtain exposure to certain markets (except for forward currency agreements). The Fund also may use futures contracts on equity securities and indices to gain market exposure on its uninvested cash.

Management process

The Advisor seeks to invest in companies that the Advisor believes are attractively valued, that integrate sustainability factors into the business model to build a competitive advantage, whose products and services can create meaningful, intentional, verifiable and measurable impact on society and the environment; and which have a clearly identified potential for additional positive impact that the Advisor intends to drive through engagement with the companies. In selecting individual securities for investment, the Advisor considers, among other factors:

•  Its assessment of fundamental valuation (price/intrinsic value) to seek attractively valued companies with strong financial performance;

•  Quantitative and qualitative environmental, social and governance ("ESG") factors;

•  Quantitative and qualitative assessment of a company's current and potential impact on society and the environment; and

•  Advisor's ability to drive positive change in a company's impact profile through engagement.

The Advisor aims to identify the best investment ideas with additional impact potential across the market capitalization spectrum, sectors and geographies within the eligible investment universe ("the impact universe").

The impact universe is comprised of companies whose products and services can create measurable, verifiable impact within specific impact categories (such as climate change, air pollution, clean water and water scarcity, treatment of disease and food security and others) that are aligned with the United Nations Sustainable Development Goals. The Advisor's assessment of the ability of public companies to generate impact is based upon impact measurement methodologies the Advisor has developed in partnership with academics from the fields of earth sciences and public health science. The impact of portfolio holdings is measured in changes in human well-being and changes in environmental quality (e.g. reduction in air pollution, hospitalizations and biodiversity loss).

Engagement with portfolio companies is a key aspect of the Fund's strategy. Companies have the potential to create additional impact through improving or optimizing the use of their products and services throughout society as well as indirectly through changes to their operations and supply chain. The Advisor's Global Sustainable Equities team and the Sustainable Research staff will seek to increase impact at each portfolio company through engagement on both fronts through communication with company management and continuous monitoring of the company's ESG impact. The Advisor will establish specific impact goals, and measure and evaluate progress regularly in order to assess the impact of its engagement efforts. The purpose of engagement with companies is to:

•  Improve the Advisor's ability to independently measure impact;

•  Engage the company to help it inform its strategy with regard to societal goals;

•  Engage the company to help increase its product and service impact by identifying target markets, customers and business partners that create additional impact over time; and

•  Engage the company to identify business model risks and opportunities linked to the ESG component of operations, supply chains and other aspects of the company that can help increase positive impact over time.

The Advisor will employ both a positive and negative screening process with regard to securities selection for the Fund. The negative screening process will exclude securities of companies with more than 5% of sales in alcohol, tobacco, defense, nuclear, gambling and pornography from the Fund's portfolio. The Advisor may modify this list of negative screens at any time, without shareholder approval or notice. The positive screening process seeks to identify securities of companies that provide solutions to significant global challenges through the impact of their products and services, that are attractive based on their fundamental and valuation profile in addition to evaluating specific sustainability (ESG) factors as well as the ability of the Advisor to engage with the company's management on impact-related issues.

Risk [Heading]

rr_RiskHeading

Main risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry a certain amount of risk, and the Fund cannot guarantee that it will achieve its investment objective. You may lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Below are some of the specific risks of investing in the Fund.

Derivatives risk: The value of "derivatives"—so called because their value "derives" from the value of an underlying asset, reference rate or index—may rise or fall more rapidly than other investments. It is possible for the Fund to lose more than the amount it invested in the derivative. The risks of investing in derivative instruments also include market risk, management risk, counterparty risk (which is the risk that a counterparty to a derivative contract is unable or unwilling to meet its financial obligations) and the risk that changes in the value of a derivative may not correlate perfectly with the underlying asset, rate, index or overall market securities. In addition, non-exchange traded derivatives may be subject to liquidity risk, credit risk and mispricing or valuation complexity. These derivatives risks are different from, and may be greater than, the risks associated with investing directly in securities and other instruments.

Emerging market risk: There are additional risks inherent in investing in less developed countries that are applicable to the Fund. Compared to the United States and other developed countries, investments in emerging market issuers may decline in value because of unfavorable foreign government actions, greater risks of political instability or the absence of accurate information about emerging market issuers. Further, emerging countries may have economies based on only a few industries and securities markets that trade only a small number of securities and employ settlement procedures different from those used in the United States. Prices on these exchanges tend to be volatile and, in the past, securities in these countries have offered greater potential for gain (as well as loss) than securities of companies located in developed countries. Further, investments by foreign investors are subject to a variety of restrictions in many emerging countries. Countries such as those in which the Fund may invest may experience, high rates of inflation, high interest rates, exchange rate fluctuations or currency depreciation, large amounts of external debt, balance of payments and trade difficulties and extreme poverty and unemployment.

Foreign investing risk: The value of the Fund's investments in foreign securities may fall due to adverse political, social and economic developments abroad and due to decreases in foreign currency values relative to the US dollar. Investments in foreign government bonds involve special risks because the Fund may have limited legal recourse in the event of default. Also, foreign securities are sometimes less liquid and more difficult to sell and to value than securities of US issuers. These risks are greater for investments in emerging market issuers.

Geographic concentration risk: The risk that if the Fund has most of its investments in a single country or region, its portfolio will be more susceptible to factors adversely affecting issuers located in that country or region than would a more geographically diverse portfolio of securities.

Investing in ETFs risk: The Fund's investment in ETFs may subject the Fund to additional risks than if the Fund would have invested directly in the ETF's underlying securities. These risks include the possibility that an ETF may experience a lack of liquidity that can result in greater volatility than its underlying securities; an ETF may trade at a premium or discount to its net asset value; or an ETF may not replicate exactly the performance of the benchmark index it seeks to track. In addition, investing in an ETF may also be more costly than if a Fund had owned the underlying securities directly. The Fund, and indirectly, shareholders of the Fund, bear a proportionate share of the ETF's expenses, which include management and advisory fees and other expenses. In addition, the Fund will pay brokerage commissions in connection with the purchase and sale.

Leverage risk associated with financial instruments: The use of financial instruments to increase potential returns, including derivatives used for investment (non-hedging) purposes, may cause the Fund to be more volatile than if it had not been leveraged. The use of leverage may also accelerate the velocity of losses and can result in losses to the Fund that exceed the amount originally invested.

Management risk: The risk that the investment strategies, techniques and risk analyses employed by the Advisor may not produce the desired results.

Market risk: The market value of the Fund's investments may fluctuate, sometimes rapidly or unpredictably, as the stock and bond markets fluctuate. Market risk may affect a single issuer, industry, or sector of the economy, or it may affect the market as a whole.

Small- and mid-capitalization risk: The risk that securities of smaller capitalization companies tend to be more volatile and less liquid than securities of larger capitalization companies. This can have a disproportionate effect on the market price of smaller capitalization companies and affect the Fund's ability to purchase or sell these securities. In general, smaller capitalization companies are more vulnerable than larger companies to adverse business or economic developments and they may have more limited resources.

Sustainability factor risk and risk of impact investing: The Fund's sustainability factors used in its investment process and the Advisor's impact investing approach will likely make the Fund perform differently from a fund that relies solely or primarily on financial metrics. The sustainability factors and the Advisor's impact investing approach may cause the Fund's industry allocation to deviate from that of funds without these considerations.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

There is no performance information quoted for the Fund as the Fund had not commenced investment operations as of the date of this prospectus.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

There is no performance information quoted for the Fund as the Fund had not commenced investment operations as of the date of this prospectus.

UBS Engage For Impact Fund | Class A

Risk/Return:

rr_RiskReturnAbstract

Maximum front-end sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.50%

Maximum contingent deferred sales charge (load) (CDSC) (as a % of purchase or sales price, whichever is less)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

^[1]

Management fees

rr_ManagementFeesOverAssets

0.75%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

0.44%

^[2]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.44%

Less management fee waiver/expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

0.34%

^[3]

Total annual fund operating expenses after management fee waiver/expense reimbursements

rr_NetExpensesOverAssets

1.10%

^[3]

Expenses Deferred Charges [Text Block]

rr_ExpensesDeferredChargesTextBlock

Purchases of $1 million or more that were not subject to a front-end sales charge are subject to a 1% CDSC if sold within one year of the purchase date.

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 656

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 949

UBS Engage For Impact Fund | Class P

Risk/Return:

rr_RiskReturnAbstract

Maximum front-end sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) (CDSC) (as a % of purchase or sales price, whichever is less)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.75%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.44%

^[2]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.19%

Less management fee waiver/expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

0.34%

^[3]

Total annual fund operating expenses after management fee waiver/expense reimbursements

rr_NetExpensesOverAssets

0.85%

^[3]

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 87

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 344

[1] Purchases of $1 million or more that were not subject to a front-end sales charge are subject to a 1% CDSC if sold within one year of the purchase date.

[2] "Other expenses" are based on estimates for the current fiscal year.

[3] The Trust, with respect to the Fund, and UBS Asset Management (Americas) Inc., the Fund's investment advisor and administrator ("UBS AM (Americas)" or the "Advisor"), have entered into a written agreement pursuant to which the Advisor has agreed to waive a portion of its management fees and/or to reimburse expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions and extraordinary expenses) to the extent necessary so that the Fund's ordinary operating expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions and extraordinary expenses), through the period ending October 29, 2019, do not exceed 1.10% for Class A shares and 0.85% for Class P shares. Pursuant to the written agreement, the Advisor is entitled to be reimbursed for any fees it waives and expenses it reimburses to the extent such reimbursement can be made during the three fiscal years following the date on which such fee waivers and expense reimbursements were made, provided that the reimbursement of the Advisor by the Fund will not cause the Fund to exceed the lesser of any applicable expense limit that is in place for the Fund (i) at the time of the waiver or reimbursement or (ii) at the time of the recoupment. The fee waiver/expense reimbursement agreement may be terminated by the Fund's Board of Trustees at any time and also will terminate automatically upon the expiration or termination of the Fund's advisory contract with the Advisor. Upon termination of the fee waiver/expense reimbursement agreement, however, UBS AM (Americas)'s three year recoupment rights will survive.

XML

Class A and P Prospectus | UBS Sustainable Development Bank Bond Fund

UBS Sustainable Development Bank Bond Fund

Investment objective

The Fund seeks current income.

Fees and expenses

These tables describe the fees and expenses that you may pay if you buy and hold shares of the Fund.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees - Class A and P Prospectus - UBS Sustainable Development Bank Bond Fund	Class A		Class P
Maximum front-end sales charge (load) imposed on purchases (as a % of offering price)	none		none
Maximum contingent deferred sales charge (load) (CDSC) (as a % of purchase or sales price, whichever is less)	none	[1]	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses - Class A and P Prospectus - UBS Sustainable Development Bank Bond Fund		Class A	Class P
Management fees		0.15%	0.15%
Distribution and/or service (12b-1) fees		0.10%	none
Other expenses	[1]	0.48%	0.48%
Total annual fund operating expenses		0.73%	0.63%
Less management fee waiver/expense reimbursements	[2]	0.38%	0.38%
Total annual fund operating expenses after management fee waiver/expense reimbursements	[2]	0.35%	0.25%

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods unless otherwise stated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The costs described in the example reflect the expenses of the Fund that would result from the contractual fee waiver and expense reimbursement agreement with the Advisor for the first year only. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Expense Example - Class A and P Prospectus - UBS Sustainable Development Bank Bond Fund - USD ($)	1 year	3 years
Class A	36	195
Class P	26	163

Portfolio turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. Because the Fund had not yet commenced operations as of the date of this prospectus, it does not have a portfolio turnover rate to provide.

Principal strategies

Principal investments

Under normal circumstances, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes, if any) in bonds and/or instruments that provide exposure to bonds issued by development banks. Development banks are financial organizations formed by government entities to promote economic and social development. The Fund invests in multilateral development bank bonds but may also invest in regional or national development bank obligations. The Fund's investment in obligations issued by the International Bank for Reconstruction and Development and the Inter-American Development Bank may be significant, but the Fund normally will not invest more than 25% of its net assets in either issuer.

Under normal circumstances, the Fund will invest in securities that, at the time of purchase, possess a minimum rating of A3 by Moody's Investors Service, Inc. ("Moody's") or A- by Standard & Poor's Financial Services LLC ("S&P") or Fitch Ratings, Inc. ("Fitch"), comparably rated by another nationally recognized statistical rating organization, or, if unrated, are determined by the Advisor to be of comparable quality.

The Fund's investments in fixed income securities may have all types of interest rate payment and reset terms. The Fund generally invests only in US dollar-denominated securities.

The Fund may, but is not required to, engage in derivatives transactions. Derivatives instruments such as futures may be used for risk management purposes to hedge against a specific security or for investment (non-hedging) purposes to earn or adjust portfolio duration. The Fund does not seek to use derivatives extensively.

The Fund is a non-diversified fund.

Management process

The Advisor seeks to invest in bonds issued by development banks. The Advisor constructs the portfolio consisting of multilateral and regional development banks. The Advisor focuses primarily on bonds issued by multilateral development banks which may include, but are not limited to, the World Bank, International Bank for Reconstruction and Development, the Inter-American Development Bank, the Asian Development Bank, the African Development Bank, and the European Bank for Reconstruction and Development. Development banks are formed by their member states with the objective to provide financial and technical assistance to improve overall living standards through sustainable economic development and growth. While each development bank has a distinct focus, development banks generally use their capital for projects that seek to improve the state of the developing world, promote sustainable growth and raise living standards.

The Advisor selects investments for the Fund based on available supply and liquidity parameters (including, for example, such factors as evaluating amounts outstanding, available dealer inventory, and volumes traded in the secondary market) utilizing a stratified sampling approach (investing in a representative cross-section of the investment universe) to optimize tracking error and minimize transaction cost. The Fund will be managed relative to a composite index, which is a blend of two market indexes designed to measure the performance of the US dollar denominated multilateral development bank bond market. The Fund seeks to minimize tracking error relative to the composite index but does not seek to directly replicate the index. The Fund's composite index is the Solactive UBS Global Multilateral Development Bank Bond USD 40% 1-5 Year 60% 5-10 Year Total Return Index. (The Fund reserves the right in its discretion to change the index). The Fund's development bank bond investments may include issuers that are not part of the composite index. The Fund will seek to maintain a concentrated portfolio of development bank bonds emphasizing multilateral development banks. The portfolio management team will select the bonds in the market that meet their selection criteria with intention to provide similar risk/return characteristics as the broader development bank bond market.

The Fund may engage in active trading to adjust the portfolio in response to investor activity and to rebalance the portfolio as new development bank issuers come to the market and existing issuers enter the index or mature.

Main risks

All investments carry a certain amount of risk, and the Fund cannot guarantee that it will achieve its investment objective. You may lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Below are some of the specific risks of investing in the Fund.

Concentration risk: The Fund concentrates in the bonds of development banks. The risk that if the Fund has most of its investments in a single industry, its portfolio will be more susceptible to factors adversely affecting that industry than would a more diverse portfolio of securities.

Credit risk: The risk that the Fund could lose money if the issuer or guarantor of a fixed income security, or the counterparty to or guarantor of a derivative contract, is unable or unwilling to meet its financial obligations. This risk is likely greater for lower quality investments than for investments that are higher quality.

Derivatives risk: The value of "derivatives"—so called because their value "derives" from the value of an underlying asset, reference rate or index—may rise or fall more rapidly than other investments. It is possible for the Fund to lose more than the amount it invested in the derivative. The risks of investing in derivative instruments also include market risk, management risk, counterparty risk (which is the risk that a counterparty to a derivative contract is unable or unwilling to meet its financial obligations) and the risk that changes in the value of a derivative may not correlate perfectly with the underlying asset, rate, index or overall market security. Derivatives relating to fixed income markets are especially susceptible to interest rate risk and credit risk. These derivatives risks are different from, and may be greater than, the risks associated with investing directly in securities and other instruments.

Interest rate risk: An increase in prevailing interest rates typically causes the value of fixed income securities to fall. Changes in interest rates will likely affect the value of longer-duration fixed income securities more than shorter-duration securities and higher quality securities more than lower quality securities. When interest rates are falling, some fixed income securities provide that the issuer may repay them earlier than the maturity date, and if this occurs the Fund may have to reinvest these repayments at lower interest rates. The risks associated with rising interest rates may be more pronounced in the near future as interest rates rise from historically low rates.

Leverage risk associated with financial instruments: The use of financial instruments to increase potential returns, including derivatives used for investment (non-hedging) purposes, may cause the Fund to be more volatile than if it had not been leveraged. The use of leverage may also accelerate the velocity of losses and can result in losses to the Fund that exceed the amount originally invested.

Liquidity risk: The risk that investments cannot be readily sold at the desired time or price, and the Fund may have to accept a lower price or may not be able to sell the security at all. An inability to sell securities can adversely affect the Fund's value or prevent the Fund from taking advantage of other investment opportunities. Liquid portfolio investments may become illiquid or less liquid after purchase by the Fund due to low trading volume, adverse investor perceptions and/or other market developments. In recent years, the number and capacity of dealers that make markets in fixed income securities has decreased. Consequently, the decline in dealers engaging in market making trading activities may increase liquidity risk, which can be more pronounced in periods of market turmoil. Liquidity risk may be magnified in a rising interest rate environment or when investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity. Liquidity risk includes the risk that the Fund will experience significant net redemptions at a time when it cannot find willing buyers for its portfolio securities or can only sell its portfolio securities at a material loss.

Management risk: The risk that the investment strategies, techniques and risk analyses employed by the Advisor may not produce the desired results.

Market risk: The market value of the Fund's investments may fluctuate, sometimes rapidly or unpredictably, as the stock and bond markets fluctuate. Market risk may affect a single issuer, industry, or sector of the economy, or it may affect the market as a whole.

Non-diversification risk: The Fund is a non-diversified investment company, which means that the Fund may invest more of its assets in a smaller number of issuers than a diversified investment company. As a non-diversified fund, the Fund's share price may be more volatile, and the Fund has a greater potential to realize losses upon the occurrence of adverse events affecting a particular issuer.

Portfolio turnover risk: High portfolio turnover from frequent trading will increase the Fund's transaction costs and may increase the portion of the Fund's capital gains that are realized for tax purposes in any given year. The Fund does not restrict the frequency of trading in order to limit expenses or the tax effect that its distributions may have on shareholders.

Risks of development bank bonds: The value of the Fund's investments in bonds issued by development banks may fall due to adverse financial market developments in the United States and abroad. Borrowers from development banks include foreign countries, which may include emerging market countries, and borrowers of specific development banks also include the private sector with or without government guarantee. Therefore, negative economic, social and political developments could affect the ability of a borrower to repay its loan to the development bank and thus affect its financial condition. In addition, investments in such development bank bonds may involve special risks because the Fund may have limited legal recourse in the event of default. Also, development bank bonds may sometimes be less liquid and more difficult to sell and to value than high-quality securities of US issuers. Bonds issued by a development bank are backed by the shareholders of the development bank. The development bank may be supported via various mechanisms, including preferred creditor status, equity injections by its shareholders and callable capital, even though the latter may have never been tested with respect to an issuer. Changes in the shareholder structure of a development bank or changes in the strength of the support by its shareholders could affect the credit rating and thus the value of the bonds issued by the development bank.

Performance

There is no performance information quoted for the Fund as the Fund had not commenced investment operations as of the date of this prospectus.

[1] Shares of the Fund acquired through the exchange of shares of another Family Fund ("Family Funds" include PACE

[1] "Other expenses" are based on estimates for the current fiscal year.

[2] The Trust, with respect to the Fund, and UBS Asset Management (Americas) Inc., the Fund's investment advisor and administrator ("UBS AM (Americas)" or the "Advisor"), have entered into a written agreement pursuant to which the Advisor has agreed to waive a portion of its management fees and/or to reimburse expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions and extraordinary expenses) to the extent necessary so that the Fund's ordinary operating expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions and extraordinary expenses), through the period ending October 29, 2019, do not exceed 0.35% for Class A shares and 0.25% for Class P shares. Pursuant to the written agreement, the Advisor is entitled to be reimbursed for any fees it waives and expenses it reimburses to the extent such reimbursement can be made during the three fiscal years following the date on which such fee waivers and expense reimbursements were made, provided that the reimbursement of the Advisor by the Fund will not cause the Fund to exceed the lesser of any applicable expense limit that is in place for the Fund (i) at the time of the waiver or reimbursement or (ii) at the time of the recoupment. The fee waiver/expense reimbursement agreement may be terminated by the Fund's Board of Trustees at any time and also will terminate automatically upon the expiration or termination of the Fund's advisory contract with the Advisor. Upon termination of the fee waiver/expense reimbursement agreement, however, UBS AM (Americas)'s three year recoupment rights will survive.

XML

Label

Element

Value

Class A and P Prospectus | UBS Sustainable Development Bank Bond Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

UBS Sustainable Development Bank Bond Fund

Objective [Heading]

rr_ObjectiveHeading

Investment objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks current income.

Expense [Heading]

rr_ExpenseHeading

Fees and expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

These tables describe the fees and expenses that you may pay if you buy and hold shares of the Fund.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

Oct. 29, 2019

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. Because the Fund had not yet commenced operations as of the date of this prospectus, it does not have a portfolio turnover rate to provide.

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

"Other expenses" are based on estimates for the current fiscal year.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods unless otherwise stated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The costs described in the example reflect the expenses of the Fund that would result from the contractual fee waiver and expense reimbursement agreement with the Advisor for the first year only. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Principal investments

Under normal circumstances, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes, if any) in bonds and/or instruments that provide exposure to bonds issued by development banks. Development banks are financial organizations formed by government entities to promote economic and social development. The Fund invests in multilateral development bank bonds but may also invest in regional or national development bank obligations. The Fund's investment in obligations issued by the International Bank for Reconstruction and Development and the Inter-American Development Bank may be significant, but the Fund normally will not invest more than 25% of its net assets in either issuer.

Under normal circumstances, the Fund will invest in securities that, at the time of purchase, possess a minimum rating of A3 by Moody's Investors Service, Inc. ("Moody's") or A- by Standard & Poor's Financial Services LLC ("S&P") or Fitch Ratings, Inc. ("Fitch"), comparably rated by another nationally recognized statistical rating organization, or, if unrated, are determined by the Advisor to be of comparable quality.

The Fund's investments in fixed income securities may have all types of interest rate payment and reset terms. The Fund generally invests only in US dollar-denominated securities.

The Fund may, but is not required to, engage in derivatives transactions. Derivatives instruments such as futures may be used for risk management purposes to hedge against a specific security or for investment (non-hedging) purposes to earn or adjust portfolio duration. The Fund does not seek to use derivatives extensively.

The Fund is a non-diversified fund.

Management process

The Advisor seeks to invest in bonds issued by development banks. The Advisor constructs the portfolio consisting of multilateral and regional development banks. The Advisor focuses primarily on bonds issued by multilateral development banks which may include, but are not limited to, the World Bank, International Bank for Reconstruction and Development, the Inter-American Development Bank, the Asian Development Bank, the African Development Bank, and the European Bank for Reconstruction and Development. Development banks are formed by their member states with the objective to provide financial and technical assistance to improve overall living standards through sustainable economic development and growth. While each development bank has a distinct focus, development banks generally use their capital for projects that seek to improve the state of the developing world, promote sustainable growth and raise living standards.

The Advisor selects investments for the Fund based on available supply and liquidity parameters (including, for example, such factors as evaluating amounts outstanding, available dealer inventory, and volumes traded in the secondary market) utilizing a stratified sampling approach (investing in a representative cross-section of the investment universe) to optimize tracking error and minimize transaction cost. The Fund will be managed relative to a composite index, which is a blend of two market indexes designed to measure the performance of the US dollar denominated multilateral development bank bond market. The Fund seeks to minimize tracking error relative to the composite index but does not seek to directly replicate the index. The Fund's composite index is the Solactive UBS Global Multilateral Development Bank Bond USD 40% 1-5 Year 60% 5-10 Year Total Return Index. (The Fund reserves the right in its discretion to change the index). The Fund's development bank bond investments may include issuers that are not part of the composite index. The Fund will seek to maintain a concentrated portfolio of development bank bonds emphasizing multilateral development banks. The portfolio management team will select the bonds in the market that meet their selection criteria with intention to provide similar risk/return characteristics as the broader development bank bond market.

The Fund may engage in active trading to adjust the portfolio in response to investor activity and to rebalance the portfolio as new development bank issuers come to the market and existing issuers enter the index or mature.

Risk [Heading]

rr_RiskHeading

Main risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry a certain amount of risk, and the Fund cannot guarantee that it will achieve its investment objective. You may lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Below are some of the specific risks of investing in the Fund.

Concentration risk: The Fund concentrates in the bonds of development banks. The risk that if the Fund has most of its investments in a single industry, its portfolio will be more susceptible to factors adversely affecting that industry than would a more diverse portfolio of securities.

Credit risk: The risk that the Fund could lose money if the issuer or guarantor of a fixed income security, or the counterparty to or guarantor of a derivative contract, is unable or unwilling to meet its financial obligations. This risk is likely greater for lower quality investments than for investments that are higher quality.

Derivatives risk: The value of "derivatives"—so called because their value "derives" from the value of an underlying asset, reference rate or index—may rise or fall more rapidly than other investments. It is possible for the Fund to lose more than the amount it invested in the derivative. The risks of investing in derivative instruments also include market risk, management risk, counterparty risk (which is the risk that a counterparty to a derivative contract is unable or unwilling to meet its financial obligations) and the risk that changes in the value of a derivative may not correlate perfectly with the underlying asset, rate, index or overall market security. Derivatives relating to fixed income markets are especially susceptible to interest rate risk and credit risk. These derivatives risks are different from, and may be greater than, the risks associated with investing directly in securities and other instruments.

Interest rate risk: An increase in prevailing interest rates typically causes the value of fixed income securities to fall. Changes in interest rates will likely affect the value of longer-duration fixed income securities more than shorter-duration securities and higher quality securities more than lower quality securities. When interest rates are falling, some fixed income securities provide that the issuer may repay them earlier than the maturity date, and if this occurs the Fund may have to reinvest these repayments at lower interest rates. The risks associated with rising interest rates may be more pronounced in the near future as interest rates rise from historically low rates.

Leverage risk associated with financial instruments: The use of financial instruments to increase potential returns, including derivatives used for investment (non-hedging) purposes, may cause the Fund to be more volatile than if it had not been leveraged. The use of leverage may also accelerate the velocity of losses and can result in losses to the Fund that exceed the amount originally invested.

Liquidity risk: The risk that investments cannot be readily sold at the desired time or price, and the Fund may have to accept a lower price or may not be able to sell the security at all. An inability to sell securities can adversely affect the Fund's value or prevent the Fund from taking advantage of other investment opportunities. Liquid portfolio investments may become illiquid or less liquid after purchase by the Fund due to low trading volume, adverse investor perceptions and/or other market developments. In recent years, the number and capacity of dealers that make markets in fixed income securities has decreased. Consequently, the decline in dealers engaging in market making trading activities may increase liquidity risk, which can be more pronounced in periods of market turmoil. Liquidity risk may be magnified in a rising interest rate environment or when investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity. Liquidity risk includes the risk that the Fund will experience significant net redemptions at a time when it cannot find willing buyers for its portfolio securities or can only sell its portfolio securities at a material loss.

Management risk: The risk that the investment strategies, techniques and risk analyses employed by the Advisor may not produce the desired results.

Market risk: The market value of the Fund's investments may fluctuate, sometimes rapidly or unpredictably, as the stock and bond markets fluctuate. Market risk may affect a single issuer, industry, or sector of the economy, or it may affect the market as a whole.

Non-diversification risk: The Fund is a non-diversified investment company, which means that the Fund may invest more of its assets in a smaller number of issuers than a diversified investment company. As a non-diversified fund, the Fund's share price may be more volatile, and the Fund has a greater potential to realize losses upon the occurrence of adverse events affecting a particular issuer.

Portfolio turnover risk: High portfolio turnover from frequent trading will increase the Fund's transaction costs and may increase the portion of the Fund's capital gains that are realized for tax purposes in any given year. The Fund does not restrict the frequency of trading in order to limit expenses or the tax effect that its distributions may have on shareholders.

Risks of development bank bonds: The value of the Fund's investments in bonds issued by development banks may fall due to adverse financial market developments in the United States and abroad. Borrowers from development banks include foreign countries, which may include emerging market countries, and borrowers of specific development banks also include the private sector with or without government guarantee. Therefore, negative economic, social and political developments could affect the ability of a borrower to repay its loan to the development bank and thus affect its financial condition. In addition, investments in such development bank bonds may involve special risks because the Fund may have limited legal recourse in the event of default. Also, development bank bonds may sometimes be less liquid and more difficult to sell and to value than high-quality securities of US issuers. Bonds issued by a development bank are backed by the shareholders of the development bank. The development bank may be supported via various mechanisms, including preferred creditor status, equity injections by its shareholders and callable capital, even though the latter may have never been tested with respect to an issuer. Changes in the shareholder structure of a development bank or changes in the strength of the support by its shareholders could affect the credit rating and thus the value of the bonds issued by the development bank.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

The Fund is a non-diversified investment company, which means that the Fund may invest more of its assets in a smaller number of issuers than a diversified investment company. As a non-diversified fund, the Fund's share price may be more volatile, and the Fund has a greater potential to realize losses upon the occurrence of adverse events affecting a particular issuer.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

There is no performance information quoted for the Fund as the Fund had not commenced investment operations as of the date of this prospectus.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

There is no performance information quoted for the Fund as the Fund had not commenced investment operations as of the date of this prospectus.

Class A and P Prospectus | UBS Sustainable Development Bank Bond Fund | Class A

Risk/Return:

rr_RiskReturnAbstract

Maximum front-end sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) (CDSC) (as a % of purchase or sales price, whichever is less)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

^[1]

Management fees

rr_ManagementFeesOverAssets

0.15%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.10%

Other expenses

rr_OtherExpensesOverAssets

0.48%

^[2]

Total annual fund operating expenses

rr_ExpensesOverAssets

0.73%

Less management fee waiver/expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

0.38%

^[3]

Total annual fund operating expenses after management fee waiver/expense reimbursements

rr_NetExpensesOverAssets

0.35%

^[3]

Expenses Deferred Charges [Text Block]

rr_ExpensesDeferredChargesTextBlock

Shares of the Fund acquired through the exchange of shares of another Family Fund ("Family Funds" include PACE® Select funds, series of The UBS Funds and other funds for which UBS AM (US) serves as principal underwriter) may be subject to a deferred sales charge if you later sell the Fund shares acquired in the exchange, based on the terms of the shares of the Family Fund you originally held.

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 36

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 195

Class A and P Prospectus | UBS Sustainable Development Bank Bond Fund | Class P

Risk/Return:

rr_RiskReturnAbstract

Maximum front-end sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) (CDSC) (as a % of purchase or sales price, whichever is less)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.15%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.48%

^[2]

Total annual fund operating expenses

rr_ExpensesOverAssets

0.63%

Less management fee waiver/expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

0.38%

^[3]

Total annual fund operating expenses after management fee waiver/expense reimbursements

rr_NetExpensesOverAssets

0.25%

^[3]

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 26

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 163

[1] Shares of the Fund acquired through the exchange of shares of another Family Fund ("Family Funds" include PACE

[2] "Other expenses" are based on estimates for the current fiscal year.

[3] The Trust, with respect to the Fund, and UBS Asset Management (Americas) Inc., the Fund's investment advisor and administrator ("UBS AM (Americas)" or the "Advisor"), have entered into a written agreement pursuant to which the Advisor has agreed to waive a portion of its management fees and/or to reimburse expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions and extraordinary expenses) to the extent necessary so that the Fund's ordinary operating expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions and extraordinary expenses), through the period ending October 29, 2019, do not exceed 0.35% for Class A shares and 0.25% for Class P shares. Pursuant to the written agreement, the Advisor is entitled to be reimbursed for any fees it waives and expenses it reimburses to the extent such reimbursement can be made during the three fiscal years following the date on which such fee waivers and expense reimbursements were made, provided that the reimbursement of the Advisor by the Fund will not cause the Fund to exceed the lesser of any applicable expense limit that is in place for the Fund (i) at the time of the waiver or reimbursement or (ii) at the time of the recoupment. The fee waiver/expense reimbursement agreement may be terminated by the Fund's Board of Trustees at any time and also will terminate automatically upon the expiration or termination of the Fund's advisory contract with the Advisor. Upon termination of the fee waiver/expense reimbursement agreement, however, UBS AM (Americas)'s three year recoupment rights will survive.

XML

Class P2 Prospectus | UBS Sustainable Development Bank Bond Fund

UBS Sustainable Development Bank Bond Fund

Investment objective

The Fund seeks current income.

Fees and expenses

These tables describe the fees and expenses that you may pay if you buy and hold shares of the Fund. Shares of Class P2 are available for purchase on behalf of clients of a fee-based program or certain other advisory programs in which UBS Asset Management (Americas) Inc., the Fund's investment advisor and administrator ("UBS AM (Americas)" or the "Advisor"), exercises investment discretion. Clients pay a wrap fee or a similar advisory fee to participate in such programs. Shares of Class P2 are also available for purchase on behalf of institutional clients with which the Advisor or its affiliates has signed a separate investment management agreement, pursuant to which such clients pay an advisory fee.

Shareholder fees (fees paid directly from your investment)

Shareholder Fees	Class P2 Prospectus UBS Sustainable Development Bank Bond Fund Class P2
Maximum front-end sales charge (load) imposed on purchases (as a % of offering price)	none
Maximum contingent deferred sales charge (load) (CDSC) (as a % of purchase or sales price, whichever is less)	none

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Class P2 Prospectus UBS Sustainable Development Bank Bond Fund Class P2
Management fees	0.15%
Distribution and/or service (12b-1) fees	none
Other expenses	0.48%	[1]
Total annual fund operating expenses	0.63%
Less management fee waiver/expense reimbursements	0.48%	[2]
Total annual fund operating expenses after management fee waiver/expense reimbursement	0.15%	[2]

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods unless otherwise stated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The costs described in the example reflect the expenses of the Fund that would result from the contractual fee waiver and expense reimbursement agreement with the Advisor for the first year only. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Expense Example	1 year	3 years
Class P2 Prospectus | UBS Sustainable Development Bank Bond Fund | Class P2 | USD ($)	15	153

Portfolio turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. Because the Fund had not yet commenced operations as of the date of this prospectus, it does not have a portfolio turnover rate to provide.

Principal strategies

Principal investments

Under normal circumstances, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes, if any) in bonds and/or instruments that provide exposure to bonds issued by development banks. Development banks are financial organizations formed by government entities to promote economic and social development. The Fund invests in multilateral development bank bonds but may also invest in regional or national development bank obligations. The Fund's investment in obligations issued by the International Bank for Reconstruction and Development and the Inter-American Development Bank may be significant, but the Fund normally will not invest more than 25% of its net assets in either issuer.

Under normal circumstances, the Fund will invest in securities that, at the time of purchase, possess a minimum rating of A3 by Moody's Investors Service, Inc. ("Moody's") or A- by Standard & Poor's Financial Services LLC ("S&P") or Fitch Ratings, Inc. ("Fitch"), comparably rated by another nationally recognized statistical rating organization, or, if unrated, are determined by the Advisor to be of comparable quality.

The Fund's investments in fixed income securities may have all types of interest rate payment and reset terms. The Fund generally invests only in US dollar-denominated securities.

The Fund may, but is not required to, engage in derivatives transactions. Derivatives instruments such as futures may be used for risk management purposes to hedge against a specific security or for investment (non-hedging) purposes to earn or adjust portfolio duration. The Fund does not seek to use derivatives extensively.

The Fund is a non-diversified fund.

Management process

The Advisor seeks to invest in bonds issued by development banks. The Advisor constructs the portfolio consisting of multilateral and regional development banks. The Advisor focuses primarily on bonds issued by multilateral development banks which may include, but are not limited to, the World Bank, International Bank for Reconstruction and Development, the Inter-American Development Bank, the Asian Development Bank, the African Development Bank, and the European Bank for Reconstruction and Development. Development banks are formed by their member states with the objective to provide financial and technical assistance to improve overall living standards through sustainable economic development and growth. While each development bank has a distinct focus, development banks generally use their capital for projects that seek to improve the state of the developing world, promote sustainable growth and raise living standards.

The Advisor selects investments for the Fund based on available supply and liquidity parameters (including, for example, such factors as evaluating amounts outstanding, available dealer inventory, and volumes traded in the secondary market) utilizing a stratified sampling approach (investing in a representative cross-section of the investment universe) to optimize tracking error and minimize transaction cost. The Fund will be managed relative to a composite index, which is a blend of two market indexes designed to measure the performance of the US dollar denominated multilateral development bank bond market. The Fund seeks to minimize tracking error relative to the composite index but does not seek to directly replicate the index. The Fund's composite index is the Solactive UBS Global Multilateral Development Bank Bond USD 40% 1-5 Year 60% 5-10 Year Total Return Index. (The Fund reserves the right in its discretion to change the index). The Fund's development bank bond investments may include issuers that are not part of the composite index. The Fund will seek to maintain a concentrated portfolio of development bank bonds emphasizing multilateral development banks. The portfolio management team will select the bonds in the market that meet their selection criteria with intention to provide similar risk/return characteristics as the broader development bank bond market.

The Fund may engage in active trading to adjust the portfolio in response to investor activity and to rebalance the portfolio as new development bank issuers come to the market and existing issuers enter the index or mature.

Main risks

All investments carry a certain amount of risk, and the Fund cannot guarantee that it will achieve its investment objective. You may lose money by investing in a Fund. An investment in the Fund is not a deposit of the bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Below are some of the specific risks of investing in the Fund.

Concentration risk: The Fund concentrates in the bonds of development banks. The risk that if the Fund has most of its investments in a single industry, its portfolio will be more susceptible to factors adversely affecting that industry than would a more diverse portfolio of securities.

Credit risk: The risk that the Fund could lose money if the issuer or guarantor of a fixed income security, or the counterparty to or guarantor of a derivative contract, is unable or unwilling to meet its financial obligations. This risk is likely greater for lower quality investments than for investments that are higher quality.

Derivatives risk: The value of "derivatives"—so called because their value "derives" from the value of an underlying asset, reference rate or index—may rise or fall more rapidly than other investments. It is possible for the Fund to lose more than the amount it invested in the derivative. The risks of investing in derivative instruments also include market risk, management risk, counterparty risk (which is the risk that a counterparty to a derivative contract is unable or unwilling to meet its financial obligations) and the risk that changes in the value of a derivative may not correlate perfectly with the underlying asset, rate, index or overall market security. Derivatives relating to fixed income markets are especially susceptible to interest rate risk and credit risk. These derivatives risks are different from, and may be greater than, the risks associated with investing directly in securities and other instruments.

Interest rate risk: An increase in prevailing interest rates typically causes the value of fixed income securities to fall. Changes in interest rates will likely affect the value of longer-duration fixed income securities more than shorter-duration securities and higher quality securities more than lower quality securities. When interest rates are falling, some fixed income securities provide that the issuer may repay them earlier than the maturity date, and if this occurs the Fund may have to reinvest these repayments at lower interest rates. The risks associated with rising interest rates may be more pronounced in the near future as interest rates rise from historically low rates.

Leverage risk associated with financial instruments: The use of financial instruments to increase potential returns, including derivatives used for investment (non-hedging) purposes, may cause the Fund to be more volatile than if it had not been leveraged. The use of leverage may also accelerate the velocity of losses and can result in losses to the Fund that exceed the amount originally invested.

Liquidity risk: The risk that investments cannot be readily sold at the desired time or price, and the Fund may have to accept a lower price or may not be able to sell the security at all. An inability to sell securities can adversely affect the Fund's value or prevent the Fund from taking advantage of other investment opportunities. Liquid portfolio investments may become illiquid or less liquid after purchase by the Fund due to low trading volume, adverse investor perceptions and/or other market developments. In recent years, the number and capacity of dealers that make markets in fixed income securities has decreased. Consequently, the decline in dealers engaging in market making trading activities may increase liquidity risk, which can be more pronounced in periods of market turmoil. Liquidity risk may be magnified in a rising interest rate environment or when investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity. Liquidity risk includes the risk that the Fund will experience significant net redemptions at a time when it cannot find willing buyers for its portfolio securities or can only sell its portfolio securities at a material loss.

Management risk: The risk that the investment strategies, techniques and risk analyses employed by the Advisor may not produce the desired results.

Market risk: The market value of the Fund's investments may fluctuate, sometimes rapidly or unpredictably, as the stock and bond markets fluctuate. Market risk may affect a single issuer, industry, or sector of the economy, or it may affect the market as a whole.

Non-diversification risk: The Fund is a non-diversified investment company, which means that the Fund may invest more of its assets in a smaller number of issuers than a diversified investment company. As a non-diversified fund, the Fund's share price may be more volatile, and the Fund has a greater potential to realize losses upon the occurrence of adverse events affecting a particular issuer.

Portfolio turnover risk: High portfolio turnover from frequent trading will increase the Fund's transaction costs and may increase the portion of the Fund's capital gains that are realized for tax purposes in any given year. The Fund does not restrict the frequency of trading in order to limit expenses or the tax effect that its distributions may have on shareholders.

Risks of development bank bonds: The value of the Fund's investments in bonds issued by development banks may fall due to adverse financial market developments in the United States and abroad. Borrowers from development banks include foreign countries, which may include emerging market countries, and borrowers of specific development banks also include the private sector with or without government guarantee. Therefore, negative economic, social and political developments could affect the ability of a borrower to repay its loan to the development bank and thus affect its financial condition. In addition, investments in such development bank bonds may involve special risks because the Fund may have limited legal recourse in the event of default. Also, development bank bonds may sometimes be less liquid and more difficult to sell and to value than high-quality securities of US issuers. Bonds issued by a development bank are backed by the shareholders of the development bank. The development bank may be supported via various mechanisms including, preferred creditor status, equity injections by its shareholders and callable capital, even though the latter may have never been tested with respect to an issuer. Changes in the shareholder structure of a development bank or changes in the strength of the support by its shareholders could affect the credit rating and thus the value of the bonds issued by the development bank.

Performance

There is no performance information quoted for the Fund as the Fund had not commenced investment operations as of the date of this prospectus.

[1] "Other expenses" are based on estimates for the current fiscal year.

[2] The Trust, with respect to the Fund, and the Advisor, have entered into a written agreement pursuant to which the Advisor has agreed to waive its management fees and retained administration fees, and to reimburse expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions and extraordinary expenses) to the extent necessary so that the Fund's ordinary operating expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions and extraordinary expenses) through the period ending October 29, 2019 do not exceed 0.15%. Pursuant to the expense limitation agreement, the Advisor is entitled to be reimbursed for any expenses it reimburses to the extent such reimbursement can be made during the three fiscal years following the date on which such expense reimbursements were made, provided that the reimbursement of the Advisor by the Fund will not cause the Fund to exceed the lesser of any applicable expense limit that is in place for the Fund (i) at the time of the reimbursement or (ii) at the time of the recoupment. The expense limitation agreement may be terminated by the Fund's Board of Trustees at any time and also will terminate automatically upon the expiration or termination of the Fund's advisory contract with the Advisor. Upon termination of the expense limitation agreement, however, the Advisor's three year recoupment rights will survive.

XML

Label

Element

Value

Class P2 Prospectus | UBS Sustainable Development Bank Bond Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

UBS Sustainable Development Bank Bond Fund

Objective [Heading]

rr_ObjectiveHeading

Investment objective

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

The Fund seeks current income.

Expense [Heading]

rr_ExpenseHeading

Fees and expenses

Expense Narrative [Text Block]

rr_ExpenseNarrativeTextBlock

These tables describe the fees and expenses that you may pay if you buy and hold shares of the Fund. Shares of Class P2 are available for purchase on behalf of clients of a fee-based program or certain other advisory programs in which UBS Asset Management (Americas) Inc., the Fund's investment advisor and administrator ("UBS AM (Americas)" or the "Advisor"), exercises investment discretion. Clients pay a wrap fee or a similar advisory fee to participate in such programs. Shares of Class P2 are also available for purchase on behalf of institutional clients with which the Advisor or its affiliates has signed a separate investment management agreement, pursuant to which such clients pay an advisory fee.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

Oct. 29, 2019

Portfolio Turnover [Heading]

rr_PortfolioTurnoverHeading

Portfolio turnover

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. Because the Fund had not yet commenced operations as of the date of this prospectus, it does not have a portfolio turnover rate to provide.

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

"Other expenses" are based on estimates for the current fiscal year.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods unless otherwise stated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The costs described in the example reflect the expenses of the Fund that would result from the contractual fee waiver and expense reimbursement agreement with the Advisor for the first year only. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Strategy [Heading]

rr_StrategyHeading

Principal strategies

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Principal investments

Under normal circumstances, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes, if any) in bonds and/or instruments that provide exposure to bonds issued by development banks. Development banks are financial organizations formed by government entities to promote economic and social development. The Fund invests in multilateral development bank bonds but may also invest in regional or national development bank obligations. The Fund's investment in obligations issued by the International Bank for Reconstruction and Development and the Inter-American Development Bank may be significant, but the Fund normally will not invest more than 25% of its net assets in either issuer.

Under normal circumstances, the Fund will invest in securities that, at the time of purchase, possess a minimum rating of A3 by Moody's Investors Service, Inc. ("Moody's") or A- by Standard & Poor's Financial Services LLC ("S&P") or Fitch Ratings, Inc. ("Fitch"), comparably rated by another nationally recognized statistical rating organization, or, if unrated, are determined by the Advisor to be of comparable quality.

The Fund's investments in fixed income securities may have all types of interest rate payment and reset terms. The Fund generally invests only in US dollar-denominated securities.

The Fund may, but is not required to, engage in derivatives transactions. Derivatives instruments such as futures may be used for risk management purposes to hedge against a specific security or for investment (non-hedging) purposes to earn or adjust portfolio duration. The Fund does not seek to use derivatives extensively.

The Fund is a non-diversified fund.

Management process

The Advisor seeks to invest in bonds issued by development banks. The Advisor constructs the portfolio consisting of multilateral and regional development banks. The Advisor focuses primarily on bonds issued by multilateral development banks which may include, but are not limited to, the World Bank, International Bank for Reconstruction and Development, the Inter-American Development Bank, the Asian Development Bank, the African Development Bank, and the European Bank for Reconstruction and Development. Development banks are formed by their member states with the objective to provide financial and technical assistance to improve overall living standards through sustainable economic development and growth. While each development bank has a distinct focus, development banks generally use their capital for projects that seek to improve the state of the developing world, promote sustainable growth and raise living standards.

The Advisor selects investments for the Fund based on available supply and liquidity parameters (including, for example, such factors as evaluating amounts outstanding, available dealer inventory, and volumes traded in the secondary market) utilizing a stratified sampling approach (investing in a representative cross-section of the investment universe) to optimize tracking error and minimize transaction cost. The Fund will be managed relative to a composite index, which is a blend of two market indexes designed to measure the performance of the US dollar denominated multilateral development bank bond market. The Fund seeks to minimize tracking error relative to the composite index but does not seek to directly replicate the index. The Fund's composite index is the Solactive UBS Global Multilateral Development Bank Bond USD 40% 1-5 Year 60% 5-10 Year Total Return Index. (The Fund reserves the right in its discretion to change the index). The Fund's development bank bond investments may include issuers that are not part of the composite index. The Fund will seek to maintain a concentrated portfolio of development bank bonds emphasizing multilateral development banks. The portfolio management team will select the bonds in the market that meet their selection criteria with intention to provide similar risk/return characteristics as the broader development bank bond market.

The Fund may engage in active trading to adjust the portfolio in response to investor activity and to rebalance the portfolio as new development bank issuers come to the market and existing issuers enter the index or mature.

Risk [Heading]

rr_RiskHeading

Main risks

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

All investments carry a certain amount of risk, and the Fund cannot guarantee that it will achieve its investment objective. You may lose money by investing in a Fund. An investment in the Fund is not a deposit of the bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Below are some of the specific risks of investing in the Fund.

Concentration risk: The Fund concentrates in the bonds of development banks. The risk that if the Fund has most of its investments in a single industry, its portfolio will be more susceptible to factors adversely affecting that industry than would a more diverse portfolio of securities.

Credit risk: The risk that the Fund could lose money if the issuer or guarantor of a fixed income security, or the counterparty to or guarantor of a derivative contract, is unable or unwilling to meet its financial obligations. This risk is likely greater for lower quality investments than for investments that are higher quality.

Derivatives risk: The value of "derivatives"—so called because their value "derives" from the value of an underlying asset, reference rate or index—may rise or fall more rapidly than other investments. It is possible for the Fund to lose more than the amount it invested in the derivative. The risks of investing in derivative instruments also include market risk, management risk, counterparty risk (which is the risk that a counterparty to a derivative contract is unable or unwilling to meet its financial obligations) and the risk that changes in the value of a derivative may not correlate perfectly with the underlying asset, rate, index or overall market security. Derivatives relating to fixed income markets are especially susceptible to interest rate risk and credit risk. These derivatives risks are different from, and may be greater than, the risks associated with investing directly in securities and other instruments.

Interest rate risk: An increase in prevailing interest rates typically causes the value of fixed income securities to fall. Changes in interest rates will likely affect the value of longer-duration fixed income securities more than shorter-duration securities and higher quality securities more than lower quality securities. When interest rates are falling, some fixed income securities provide that the issuer may repay them earlier than the maturity date, and if this occurs the Fund may have to reinvest these repayments at lower interest rates. The risks associated with rising interest rates may be more pronounced in the near future as interest rates rise from historically low rates.

Leverage risk associated with financial instruments: The use of financial instruments to increase potential returns, including derivatives used for investment (non-hedging) purposes, may cause the Fund to be more volatile than if it had not been leveraged. The use of leverage may also accelerate the velocity of losses and can result in losses to the Fund that exceed the amount originally invested.

Liquidity risk: The risk that investments cannot be readily sold at the desired time or price, and the Fund may have to accept a lower price or may not be able to sell the security at all. An inability to sell securities can adversely affect the Fund's value or prevent the Fund from taking advantage of other investment opportunities. Liquid portfolio investments may become illiquid or less liquid after purchase by the Fund due to low trading volume, adverse investor perceptions and/or other market developments. In recent years, the number and capacity of dealers that make markets in fixed income securities has decreased. Consequently, the decline in dealers engaging in market making trading activities may increase liquidity risk, which can be more pronounced in periods of market turmoil. Liquidity risk may be magnified in a rising interest rate environment or when investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity. Liquidity risk includes the risk that the Fund will experience significant net redemptions at a time when it cannot find willing buyers for its portfolio securities or can only sell its portfolio securities at a material loss.

Management risk: The risk that the investment strategies, techniques and risk analyses employed by the Advisor may not produce the desired results.

Market risk: The market value of the Fund's investments may fluctuate, sometimes rapidly or unpredictably, as the stock and bond markets fluctuate. Market risk may affect a single issuer, industry, or sector of the economy, or it may affect the market as a whole.

Non-diversification risk: The Fund is a non-diversified investment company, which means that the Fund may invest more of its assets in a smaller number of issuers than a diversified investment company. As a non-diversified fund, the Fund's share price may be more volatile, and the Fund has a greater potential to realize losses upon the occurrence of adverse events affecting a particular issuer.

Portfolio turnover risk: High portfolio turnover from frequent trading will increase the Fund's transaction costs and may increase the portion of the Fund's capital gains that are realized for tax purposes in any given year. The Fund does not restrict the frequency of trading in order to limit expenses or the tax effect that its distributions may have on shareholders.

Risks of development bank bonds: The value of the Fund's investments in bonds issued by development banks may fall due to adverse financial market developments in the United States and abroad. Borrowers from development banks include foreign countries, which may include emerging market countries, and borrowers of specific development banks also include the private sector with or without government guarantee. Therefore, negative economic, social and political developments could affect the ability of a borrower to repay its loan to the development bank and thus affect its financial condition. In addition, investments in such development bank bonds may involve special risks because the Fund may have limited legal recourse in the event of default. Also, development bank bonds may sometimes be less liquid and more difficult to sell and to value than high-quality securities of US issuers. Bonds issued by a development bank are backed by the shareholders of the development bank. The development bank may be supported via various mechanisms including, preferred creditor status, equity injections by its shareholders and callable capital, even though the latter may have never been tested with respect to an issuer. Changes in the shareholder structure of a development bank or changes in the strength of the support by its shareholders could affect the credit rating and thus the value of the bonds issued by the development bank.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in a Fund.

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

The Fund is a non-diversified investment company, which means that the Fund may invest more of its assets in a smaller number of issuers than a diversified investment company. As a non-diversified fund, the Fund's share price may be more volatile, and the Fund has a greater potential to realize losses upon the occurrence of adverse events affecting a particular issuer.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Performance

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

There is no performance information quoted for the Fund as the Fund had not commenced investment operations as of the date of this prospectus.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

There is no performance information quoted for the Fund as the Fund had not commenced investment operations as of the date of this prospectus.

Class P2 Prospectus | UBS Sustainable Development Bank Bond Fund | Class P2

Risk/Return:

rr_RiskReturnAbstract

Maximum front-end sales charge (load) imposed on purchases (as a % of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum contingent deferred sales charge (load) (CDSC) (as a % of purchase or sales price, whichever is less)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Management fees

rr_ManagementFeesOverAssets

0.15%

Distribution and/or service (12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.48%

^[1]

Total annual fund operating expenses

rr_ExpensesOverAssets

0.63%

Less management fee waiver/expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

0.48%

^[2]

Total annual fund operating expenses after management fee waiver/expense reimbursement

rr_NetExpensesOverAssets

0.15%

^[2]

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 15

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 153

[1] "Other expenses" are based on estimates for the current fiscal year.

[2] The Trust, with respect to the Fund, and the Advisor, have entered into a written agreement pursuant to which the Advisor has agreed to waive its management fees and retained administration fees, and to reimburse expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions and extraordinary expenses) to the extent necessary so that the Fund's ordinary operating expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions and extraordinary expenses) through the period ending October 29, 2019 do not exceed 0.15%. Pursuant to the expense limitation agreement, the Advisor is entitled to be reimbursed for any expenses it reimburses to the extent such reimbursement can be made during the three fiscal years following the date on which such expense reimbursements were made, provided that the reimbursement of the Advisor by the Fund will not cause the Fund to exceed the lesser of any applicable expense limit that is in place for the Fund (i) at the time of the reimbursement or (ii) at the time of the recoupment. The expense limitation agreement may be terminated by the Fund's Board of Trustees at any time and also will terminate automatically upon the expiration or termination of the Fund's advisory contract with the Advisor. Upon termination of the expense limitation agreement, however, the Advisor's three year recoupment rights will survive.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Prospectus Date	rr_ProspectusDate	Oct. 23, 2018