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Class P2 Prospectus | UBS International Sustainable Equity Fund

UBS International Sustainable Equity Fund

Investment objective

The Fund seeks to maximize total return, consisting of capital appreciation and current income by investing primarily in the equity securities of non-US issuers.

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 International Sustainable Equity 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 International Sustainable Equity Fund Class P2
Management fees	0.80%
Distribution and/or service (12b-1) fees	none
Other expenses	0.32%	[1]
Total annual fund operating expenses	1.12%
Less management fee waiver/expense reimbursements	0.87%	[2]
Total annual fund operating expenses after management fee waiver/expense reimbursements	0.25%	[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	5 years	10 years
Class P2 Prospectus | UBS International Sustainable Equity Fund | Class P2 | USD ($)	26	269	533	1,285

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. During the most recent fiscal year, the Fund's portfolio turnover rate was 41% of the average value of its portfolio.

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 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; equity securities of real estate investment trusts ("REITs"); and exchange-traded funds ("ETFs"). Under normal market conditions, the Fund invests primarily (at least 65% of its total assets) in issuers organized or having their principal place of business outside the United States or doing a substantial amount of business outside the United States. Up to 35% of the Fund's assets may be invested in US equity securities. The Fund may invest in issuers from both developed 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.

Under certain market conditions, the Fund may invest in companies at the time of their initial public offering ("IPO").

Management process

The Advisor's investment decisions are based upon price/value discrepancies as identified by the Advisor's fundamental valuation process.

In selecting securities for the portion of the Fund that is managed according to the Advisor's fundamental valuation process, the Advisor focuses on, among other things, identifying discrepancies between a security's fundamental value and its market price. In this context, the fundamental value of a given security is the Advisor's assessment of what a security is worth. The Advisor will select a security whose fundamental value it estimates to be greater than its market value at any given time. For each stock under analysis, the Advisor bases its estimates of value upon country, economic, industry and company analysis, as well as upon a company's management team, competitive advantage and core competencies. The Advisor then compares its assessment of a security's value against the prevailing market prices, with the aim of constructing a portfolio of stocks across industries and countries with attractive relative price/value characteristics.

The Advisor will employ both a positive and negative screening process with regard to securities selection for all equity stocks for the Fund. The negative screening process will exclude securities with more than 5% of sales in alcohol, tobacco, defense, nuclear, GMO (Genetically Modified Organisms), gambling and pornography from the Fund's portfolio. We believe that this negative screen reduces the global universe by about 6% by market capitalization, and we do not expect it to have a material impact on portfolio construction or strategy. The Advisor may modify the above list of negative screens at any time, without prior shareholder approval or notice.

The positive screening process will identify securities of companies that are attractive based on their fundamental and valuation profile in addition to evaluating specific sustainability factors.

These sustainability factors are material factors that help the Advisor evaluate and compare the environmental, social and governance performance of the investable universe. This information is combined with additional financial analysis and research to identify companies the Advisor believes will provide attractively valued and sustainable investment opportunities.

The Advisor uses an ESG Material Issues Framework to identify 3 to 5 of the most financially relevant factors, per sector, that can impact the investment thesis across different industry sectors. The universe of sustainability issues includes environmental factors such as global greenhouse gas emissions and wastewater management; social factors such as customer privacy

and product safety; and governance factors such as critical and systemic risk management.

The Advisor uses a proprietary risk tool to combine scores and data points from a number of reputable external research providers together with the UBS internal ESG model to flag companies with elevated sustainability risks. In addition, absolute ESG risks such as poor corporate governance and high ESG controversy levels are included in the Advisor's risk tool. Collectively, these inputs lead to an ESG Risk Signal which flags companies with high ESG risks. Once outliers are identified, the Advisor conducts more in-depth analysis to assess the material impact of the ESG risks.

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.

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. 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. Issuers may not be subject to uniform accounting, auditing and financial reporting standards and there may be less publicly available financial and other information about such issuers, comparable to U.S. issuers. 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.

Sustainability factor risk: Because the Fund uses sustainability factors to assess and exclude certain investments for non-financial reasons, the Fund may forego some market opportunities available to funds that do not use these factors. As a result, the Fund's sustainability factors used in its investment process will likely make the Fund perform differently from a fund that relies solely or primarily on financial metrics, and the Fund's sustainability factors may be linked to long-term rather than short-term returns. The sustainability factors may cause the Fund's industry allocation to deviate from that of funds without these considerations.

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.

IPOs risk: The purchase of shares issued in IPOs may expose the Fund to the risks associated with issuers that have no operating history as public companies, as well as to the risks associated with the sectors of the market in which the issuer operates. The market for IPO shares may be volatile, and share prices of newly-public companies may fluctuate significantly over a short period of time.

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.

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.

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.

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.

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; an ETF may not replicate exactly the performance of the benchmark index it seeks to track; trading an ETF's shares may be halted if the listing exchange's officials deem such action appropriate; and a passively managed ETF would not necessarily sell a security because the issuer of the security was in financial trouble unless the security is removed from the index that the ETF 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 of shares of the ETF.

Real estate securities and REITs risk: The risk that the Fund's performance will be affected by adverse developments in the real estate industry. Real estate values may be affected by a variety of factors, including: local, national or global economic conditions; changes in zoning or other property-related laws; environmental regulations; interest rates; tax and insurance considerations; overbuilding; property taxes and operating expenses; or declining values in a neighborhood. Similarly, a REIT's performance depends on the types, values, locations and management of the properties it owns. In addition, a REIT may be more susceptible to adverse developments affecting a single project or market segment than a more diversified investment. Loss of status as a qualified REIT under the US federal tax laws could adversely affect the value of a particular REIT or the market for REITs as a whole.

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

Performance

Risk/return bar chart and table

The performance information that follows shows the Fund's Class P performance information in a bar chart and an average annual total returns table. There is no performance information quoted for the Class P2 shares of the Fund as the Class P2 shares have not completed a full calendar year of operations as of the date of this prospectus. Although the Class P2 shares are invested in the same portfolio of securities as the Class P shares, returns for the Class P2 shares will differ from the Class P shares to the extent that the Class P2 shares are subject to different expenses. The information provides some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual total returns compare with those of a broad measure of market performance. The MSCI ACWI ex-US Index reflects no deduction for fees, expenses or taxes but is net of dividend tax withholding. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. In October 2013, the Fund's investment strategies changed. The performance below for periods prior to that date is attributable to the Fund's performance before the strategy change. Updated performance for the Fund is available at www.ubs.com/us-mutualfundperformance.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. In addition, the after-tax returns shown are not relevant to investors who hold Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for other classes will vary from the Class P shares' after-tax returns shown.

Total return (Class P)

Total return January 1 - September 30, 2020: (3.49)%
Best quarter during calendar years shown—3Q 2010: 17.29%
Worst quarter during calendar years shown—3Q 2011: (23.88)%

Average annual total returns (for the periods ended December 31, 2019)

Average Annual Returns - Class P2 Prospectus - UBS International Sustainable Equity Fund	Average Annual Returns, 1 Year	Average Annual Returns, 5 Years	Average Annual Returns, 10 Years	Average Annual Returns, Inception Date
CLASS P	22.61%	5.62%	5.83%	Aug. 31, 1993
After Taxes on Distributions | CLASS P	22.34%	5.32%	5.41%
After Taxes on Distributions and Sale of Fund Shares | CLASS P	13.82%	4.46%	4.68%
MSCI ACWI ex-US Index	21.51%	5.51%	4.97%

[1] "Other expenses" are based on estimates for the current fiscal year and include "Acquired fund fees and expenses," which were less than 0.01% of the average net assets of the Fund.

[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 28, 2021 do not exceed 0.25%. 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 years following the period during 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.