485BPOS

As filed with the U.S. Securities and Exchange Commission on March 21, 2016

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. 120	x
and/or
REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940		x

Amendment No. 121

(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

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

2600 One Commerce Square

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):

ximmediately upon filing pursuant to paragraph (b)

oon [Date] pursuant to paragraph (b)

o60 days after filing pursuant to paragraph (a)(1)

oon [Date] pursuant to paragraph (a)(1)

o75 days after filing pursuant to paragraph (a)(2)

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

If appropriate, check the following box:

oThis 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. 120/121 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 21st day of March, 2016.

THE UBS FUNDS
By:	/s/ Mark E. Carver
	Mark E. Carver*
	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/ Mark E. Carver	President and Principal Executive Officer	March 21, 2016
Mark E. Carver*
/s/ Frank K. Reilly	Chairman and Trustee	March 21, 2016
Frank K. Reilly*
/s/ E. Blake Moore, Jr.	Trustee	March 21, 2016
E. Blake Moore, Jr.*
/s/ Adela Cepeda	Trustee	March 21, 2016
Adela Cepeda*
/s/ J. Mikesell Thomas	Trustee	March 21, 2016
J. Mikesell Thomas*
/s/ Abbie J. Smith	Trustee	March 21, 2016
Abbie J. Smith*
/s/ John J. Murphy	Trustee	March 21, 2016
John J. Murphy*
/s/ Thomas Disbrow	Treasurer and Principal Accounting Officer	March 21, 2016
Thomas Disbrow*

* By:	/s/ Tammie Lee
	Tammie Lee, 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	Mar. 01, 2016
Registrant Name	UBS FUNDS
Central Index Key	0000886244
Amendment Flag	false
Document Creation Date	Mar. 01, 2016
Document Effective Date	Mar. 01, 2016
Prospectus Date	Mar. 01, 2016
UBS Total Return Bond Fund | Class A
Prospectus:
Trading Symbol	UTBAX
UBS Total Return Bond Fund | Class C
Prospectus:
Trading Symbol	UTBCX
UBS Total Return Bond Fund | Class P
Prospectus:
Trading Symbol	UTBPX

XML

UBS Total Return Bond Fund

UBS Total Return Bond 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 $100,000 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” on page 14 of the Fund’s prospectus and in “Reduced sales charges, additional purchase, exchange and redemption information and other services” on page 66 of the Fund’s statement of additional information (“SAI”).

Shareholder fees (fees paid directly from your investment)

Shareholder Fees - UBS Total Return Bond Fund	Class A		Class C	Class P
Maximum front-end sales charge (load) imposed on purchases (as a % of offering price)	3.75%		none	none
Maximum contingent deferred sales charge (load) (CDSC) (as a % of purchase or sales price, whichever is less)	none	[1]	0.75%	none
Redemption fee (as a % of amount redeemed within 90 days from the date the Fund commenced investment operations)	none		none	2.00%	[2]

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

Annual Fund Operating Expenses - UBS Total Return Bond Fund		Class A	Class C	Class P
Management fees		0.50%	0.50%	0.50%
Distribution and/or service (12b-1) fees		0.25%	0.75%	none
Other expenses	[1]	0.31%	0.31%	0.31%
Total annual fund operating expenses		1.06%	1.56%	0.81%
Less management fee waiver/expense reimbursements		0.31%	0.31%	0.31%
Total annual fund operating expenses after management fee waiver/expense reimbursements	[2]	0.75%	1.25%	0.50%

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 Total Return Bond Fund - USD ($)	1 year	3 years
Class A	449	670
Class C	202	462
Class P	51	228

Expense Example No Redemption	1 year	3 years
UBS Total Return Bond Fund | Class C | USD ($)	127	462

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 has not yet commenced operations as of the date of this prospectus, the Fund’s portfolio turnover is  not available.

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 bond markets.

For purposes of the Fund’s 80% policy above, the Fund’s investments in bonds include a variety of fixed income securities, which may include, but are not limited to, securities of the US government, its agencies and government-sponsored enterprises, securities guaranteed by the US government, corporate debt securities of US and non-US issuers, including convertible securities, obligations of non-US governments or their subdivisions, agencies and government-sponsored enterprises, obligations of international agencies or supranational entities, mortgage-backed (including commercial and residential mortgage-backed securities) and asset-backed securities, and other securitized and structured securities.

Under normal circumstances, the Fund will invest at least 75% of its net assets in securities that, at the time of purchase, are rated investment grade by an independent rating agency (or, if unrated, are deemed to be of comparable quality by the Advisor), but may invest up to 25% in securities rated below investment grade (also known as “junk bonds”).

The Fund’s investments in fixed income securities may have all types of interest rate payment and reset terms, including fixed rate, adjustable rate, zero coupon, pay-in-kind and auction rate features.  In addition, the fixed income securities purchased by the Fund may be denominated in any currency, have coupons payable in any currency and may be of any maturity or duration.

The Fund invests in the United States and abroad, including emerging markets, and may purchase securities issued by domestic and foreign issuers.  However, the Fund expects to limit foreign currency exposure to 25% of its net assets.  Furthermore, no more than 25% of the Fund’s net assets may be invested in emerging markets securities.  Depending on its assessment of market conditions, the Advisor may choose to allocate the Fund’s assets in any combination among these types of investments or may choose not to invest in these types of investments.

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, or index, and may relate to stocks, bonds, interest rates, currencies or currency exchange rates, and related indexes. The derivatives in which the Fund may invest include options (including, but not limited to, options on futures, forwards and swap agreements), futures, forward agreements, swap agreements (specifically, interest rate, total return, currency, credit default and inflation swaps), credit-linked securities and structured investments. All of these derivatives may be used for risk management purposes, such as hedging against a specific security or currency, or to manage or adjust the risk profile of the Fund. 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; to obtain exposure to certain markets; or to establish net short positions for individual sectors, markets, currencies or securities.  The Fund may use options, futures, swap agreements, credit-linked securities and structured investments to adjust the Fund’s portfolio duration.

The Fund may engage in active and frequent trading of portfolio securities to achieve its principal investment strategies.

Management process

The Advisor’s investment strategy is based on identifying compelling and attractive opportunities where the Advisor believes that the return profile sufficiently compensates for the risk of owning a position. The Advisor focuses on identifying relative value opportunities and discrepancies between observable market prices and the Advisor’s own estimates of fundamental value across various maturities, sectors and issuers.

The investment process combines both a top-down and bottom-up dynamic approach to exploit diversified sources of alpha. The Advisor makes active decisions related to top-down factors, including duration, yield curve, and sector positioning. After defining these parameters, portfolio managers and credit research analysts work in close collaboration to develop investment themes for industry overweights and underweights as well as to determine the portions of the credit curve that are most attractive. The team then works to select securities to build optimal portfolios using bottom-up research and analysis.

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 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.

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 due to the current period of historically low rates.

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.

US Government securities risk: There are different types of US government securities with different levels of credit risk, including the risk of default, depending on the nature of the particular government support for that security. For example, a US government-sponsored entity, although chartered or sponsored by an Act of Congress, may issue securities that are neither insured nor guaranteed by the US Treasury and are therefore riskier than those that are.

Illiquidity 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. Illiquidity 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. Illiquidity risk can be more pronounced in periods of market turmoil.

High yield bond risk: The risk that the issuer of municipal bonds with ratings of BB (Standard & Poor’s Financial Services LLC (“S&P”) or Fitch Ratings, Inc. (“Fitch”)) or Ba (Moody’s Investors Service, Inc. (“Moody’s”)) or below, or deemed of equivalent quality, will default or otherwise be unable to honor a financial obligation (also known as lower-rated or “junk bonds”). These securities are considered to be predominately speculative with respect to an issuer’s capacity to pay interest and repay principal in accordance with the terms of the obligations. Lower-rated municipal bonds are more likely to be subject to an issuer’s default or downgrade than investment grade (higher quality) municipal bonds.

Mortgage- and Asset-Backed Securities Risk: The Fund may invest in mortgage- and asset-backed securities that are subject to prepayment or call risk, which is the risk that the borrower's payments may be received earlier or later than expected due to changes in prepayment rates on underlying loans. Faster prepayments often happen when interest rates are falling. As a result, the Fund may reinvest these early payments at lower interest rates, thereby reducing the Fund's income. Conversely, when interest rates rise, prepayments may happen more slowly, causing the security to lengthen in duration. Longer duration securities tend to be more volatile. Securities may be prepaid at may adversely affect the value of mortgage-backed securities and could result in losses to the Fund.

Market risk: The risk that 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.

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.

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.

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 and counterparty risk (which is the risk that a counterparty to a derivative contract is unable or unwilling to meet its financial obligations). Derivatives relating to fixed income markets are especially susceptible to interest rate risk and credit risk. In addition, many types of swaps and other 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.

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.

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.

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.

[2] The Board of Trustees of the Trust has approved a temporary redemption fee for the Fund for the first 90 days of the Fund's operation following the reorganization of Fort Dearborn Income Securities, Inc., a closed-end fund, with the Fund.

[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. (formerly, UBS Global Asset Management (Americas) Inc.), the Fund's investment advisor ("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 27, 2017, do not exceed 0.75% for Class A shares, 1.25% for Class C shares and 0.50% 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 for a period of three years following such fee waivers and expense reimbursements to the extent that such reimbursement of the Advisor by the Fund will not cause the Fund to exceed any applicable expense limit that is in place for the Fund. 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, the UBS AM (Americas)'s three year recoupment rights will survive.

XML

Label

Element

Value

UBS Total Return Bond Fund

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

UBS Total Return Bond 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 $100,000 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” on page 14 of the Fund’s prospectus and in “Reduced sales charges, additional purchase, exchange and redemption information and other services” on page 66 of the Fund’s statement of additional information (“SAI”).

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. 27, 2017

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 has not yet commenced operations as of the date of this prospectus, the Fund’s portfolio turnover is  not available.

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 $100,000 in the Fund.

Expense Breakpoint, Minimum Investment Required [Amount]

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

$ 100,000

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

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 bond markets.

For purposes of the Fund’s 80% policy above, the Fund’s investments in bonds include a variety of fixed income securities, which may include, but are not limited to, securities of the US government, its agencies and government-sponsored enterprises, securities guaranteed by the US government, corporate debt securities of US and non-US issuers, including convertible securities, obligations of non-US governments or their subdivisions, agencies and government-sponsored enterprises, obligations of international agencies or supranational entities, mortgage-backed (including commercial and residential mortgage-backed securities) and asset-backed securities, and other securitized and structured securities.

Under normal circumstances, the Fund will invest at least 75% of its net assets in securities that, at the time of purchase, are rated investment grade by an independent rating agency (or, if unrated, are deemed to be of comparable quality by the Advisor), but may invest up to 25% in securities rated below investment grade (also known as “junk bonds”).

The Fund’s investments in fixed income securities may have all types of interest rate payment and reset terms, including fixed rate, adjustable rate, zero coupon, pay-in-kind and auction rate features.  In addition, the fixed income securities purchased by the Fund may be denominated in any currency, have coupons payable in any currency and may be of any maturity or duration.

The Fund invests in the United States and abroad, including emerging markets, and may purchase securities issued by domestic and foreign issuers.  However, the Fund expects to limit foreign currency exposure to 25% of its net assets.  Furthermore, no more than 25% of the Fund’s net assets may be invested in emerging markets securities.  Depending on its assessment of market conditions, the Advisor may choose to allocate the Fund’s assets in any combination among these types of investments or may choose not to invest in these types of investments.

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, or index, and may relate to stocks, bonds, interest rates, currencies or currency exchange rates, and related indexes. The derivatives in which the Fund may invest include options (including, but not limited to, options on futures, forwards and swap agreements), futures, forward agreements, swap agreements (specifically, interest rate, total return, currency, credit default and inflation swaps), credit-linked securities and structured investments. All of these derivatives may be used for risk management purposes, such as hedging against a specific security or currency, or to manage or adjust the risk profile of the Fund. 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; to obtain exposure to certain markets; or to establish net short positions for individual sectors, markets, currencies or securities.  The Fund may use options, futures, swap agreements, credit-linked securities and structured investments to adjust the Fund’s portfolio duration.

The Fund may engage in active and frequent trading of portfolio securities to achieve its principal investment strategies.

Management process

The Advisor’s investment strategy is based on identifying compelling and attractive opportunities where the Advisor believes that the return profile sufficiently compensates for the risk of owning a position. The Advisor focuses on identifying relative value opportunities and discrepancies between observable market prices and the Advisor’s own estimates of fundamental value across various maturities, sectors and issuers.

The investment process combines both a top-down and bottom-up dynamic approach to exploit diversified sources of alpha. The Advisor makes active decisions related to top-down factors, including duration, yield curve, and sector positioning. After defining these parameters, portfolio managers and credit research analysts work in close collaboration to develop investment themes for industry overweights and underweights as well as to determine the portions of the credit curve that are most attractive. The team then works to select securities to build optimal portfolios using bottom-up research and analysis.

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 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.

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 due to the current period of historically low rates.

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.

US Government securities risk: There are different types of US government securities with different levels of credit risk, including the risk of default, depending on the nature of the particular government support for that security. For example, a US government-sponsored entity, although chartered or sponsored by an Act of Congress, may issue securities that are neither insured nor guaranteed by the US Treasury and are therefore riskier than those that are.

Illiquidity 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. Illiquidity 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. Illiquidity risk can be more pronounced in periods of market turmoil.

High yield bond risk: The risk that the issuer of municipal bonds with ratings of BB (Standard & Poor’s Financial Services LLC (“S&P”) or Fitch Ratings, Inc. (“Fitch”)) or Ba (Moody’s Investors Service, Inc. (“Moody’s”)) or below, or deemed of equivalent quality, will default or otherwise be unable to honor a financial obligation (also known as lower-rated or “junk bonds”). These securities are considered to be predominately speculative with respect to an issuer’s capacity to pay interest and repay principal in accordance with the terms of the obligations. Lower-rated municipal bonds are more likely to be subject to an issuer’s default or downgrade than investment grade (higher quality) municipal bonds.

Mortgage- and Asset-Backed Securities Risk: The Fund may invest in mortgage- and asset-backed securities that are subject to prepayment or call risk, which is the risk that the borrower's payments may be received earlier or later than expected due to changes in prepayment rates on underlying loans. Faster prepayments often happen when interest rates are falling. As a result, the Fund may reinvest these early payments at lower interest rates, thereby reducing the Fund's income. Conversely, when interest rates rise, prepayments may happen more slowly, causing the security to lengthen in duration. Longer duration securities tend to be more volatile. Securities may be prepaid at may adversely affect the value of mortgage-backed securities and could result in losses to the Fund.

Market risk: The risk that 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.

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.

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.

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 and counterparty risk (which is the risk that a counterparty to a derivative contract is unable or unwilling to meet its financial obligations). Derivatives relating to fixed income markets are especially susceptible to interest rate risk and credit risk. In addition, many types of swaps and other 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.

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.

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.

Risk Lose Money [Text]

rr_RiskLoseMoney

You may lose money by investing in the Fund.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

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.

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 Total Return Bond Fund | Class A

Risk/Return:

rr_RiskReturnAbstract

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

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

3.75%

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

rr_MaximumDeferredSalesChargeOverOther

none

^[1]

Redemption Fee (as a percentage of Amount Redeemed)

rr_RedemptionFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.50%

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

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

0.31%

^[2]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.06%

Fee Waiver or Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.31%)

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

rr_NetExpensesOverAssets

0.75%

^[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

$ 449

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 670

UBS Total Return Bond Fund | Class C

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_MaximumDeferredSalesChargeOverOther

0.75%

Redemption Fee (as a percentage of Amount Redeemed)

rr_RedemptionFeeOverRedemption

none

Management fees

rr_ManagementFeesOverAssets

0.50%

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

rr_DistributionAndService12b1FeesOverAssets

0.75%

Other expenses

rr_OtherExpensesOverAssets

0.31%

^[2]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.56%

Fee Waiver or Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.31%)

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

rr_NetExpensesOverAssets

1.25%

^[3]

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 202

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

462

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

127

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

$ 462

UBS Total Return 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_MaximumDeferredSalesChargeOverOther

none

Redemption Fee (as a percentage of Amount Redeemed)

rr_RedemptionFeeOverRedemption

(2.00%)

^[4]

Management fees

rr_ManagementFeesOverAssets

0.50%

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

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.31%

^[2]

Total annual fund operating expenses

rr_ExpensesOverAssets

0.81%

Fee Waiver or Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.31%)

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

rr_NetExpensesOverAssets

0.50%

^[3]

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 51

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 228

[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. (formerly, UBS Global Asset Management (Americas) Inc.), the Fund's investment advisor ("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 27, 2017, do not exceed 0.75% for Class A shares, 1.25% for Class C shares and 0.50% 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 for a period of three years following such fee waivers and expense reimbursements to the extent that such reimbursement of the Advisor by the Fund will not cause the Fund to exceed any applicable expense limit that is in place for the Fund. 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, the UBS AM (Americas)'s three year recoupment rights will survive.

[4] The Board of Trustees of the Trust has approved a temporary redemption fee for the Fund for the first 90 days of the Fund's operation following the reorganization of Fort Dearborn Income Securities, Inc., a closed-end fund, with the Fund.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Prospectus Date	rr_ProspectusDate	Mar. 01, 2016