MainStay Epoch International Small Cap Fund		Summary Prospectus February 29, 2016
Class/Ticker	A  EPIPXInvestor EPIIXC EPIKXI  EPIEX

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Before you invest, you may want to review the Fund's Prospectus, which contains more information about the Fund and its risks. You can find the Fund's Prospectus and other information about the Fund by going online to mainstayinvestments.com/documents, by calling 800-MAINSTAY (624-6782) or by sending an e-mail to MainStayShareholderServices@nylim.com. The Fund's Prospectus and Statement of Additional Information, both dated February 29, 2016, as may be amended from time to time, are incorporated by reference into this Summary Prospectus.

Investment Objective

The Fund seeks long-term capital appreciation.

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the MainStay Funds. This amount may vary depending on the MainStay Fund in which you invest. More information about these and other discounts is available from your financial professional and in the "Information on Sales Charges" section starting on page 100 of the Prospectus and in the "Alternative Sales Arrangements" section on page 111 of the Statement of Additional Information.

		Class A		Investor  Class		Class C		Class I
Shareholder Fees (fees paid directly from your investment)
	Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.50	%	5.50	%	None		None
	Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of the original offering price or redemption proceeds)	None	1	None	1	1.00	%	None
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
	Management Fees (as an annual percentage of the Fund's average daily net assets)	1.10	%	1.10	%	1.10	%	1.10	%
	Distribution and/or Service (12b-1) Fees	0.25	%	0.25	%	1.00	%	None
	Other Expenses	0.33	%	0.56	%	0.56	%	0.33	%
	Total Annual Fund Operating Expenses	1.68	%	1.91	%	2.66	%	1.43	%
	Waivers / Reimbursements2	(0.05	)%	(0.05	)%	(0.05	)%	(0.05	)%
	Total Annual Fund Operating Expenses After Waivers / Reimbursements2	1.63	%	1.86	%	2.61	%	1.38	%

1.A contingent deferred sales charge of 1.00% may be imposed on certain redemptions made within one year of the date of purchase on shares that were purchased without an initial sales charge.

2.New York Life Investment Management LLC (“New York Life Investments”) has contractually agreed to waive a portion of its management fee so that the management fee does not exceed 1.05%. This agreement will remain in effect until March 1, 2017, and shall renew automatically for one-year terms unless New York Life Investments provides written notice of termination prior to the start of the next term or upon approval of the Board of Trustees of the Fund.

Example

The 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 redeem all of your shares at the end of those periods (except as indicated with respect to Class C shares). The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The Example reflects the contractual fee waiver and/or expense reimbursement arrangement, if applicable, for the current duration of the arrangement only. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expenses After	Class A	Investor	Class C		Class I
		Class	Assuming no redemption	Assuming redemption at end of period
1 Year	$       707	$       729	$       264	$       364	$       140
3 Years	$    1,046	$    1,112	$       822	$       822	$       448
5 Years	$    1,408	$    1,520	$    1,406	$    1,406	$       777
10 Years	$    2,424	$    2,656	$    2,989	$    2,989	$    1,709

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 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 39% of the average value of its portfolio.

(NYLIM) NL256 MSEISC01-02/16

Principal Investment Strategies

The Fund seeks to achieve its investment objective by investing in a diversified portfolio consisting mostly of equity securities of companies located outside the U.S., which may include companies in emerging markets. Under normal circumstances, the Fund will invest at least 80% of its assets (net assets plus any borrowings for investment purposes) in the equity securities of "small capitalization" companies located outside of the U.S. Equity securities include common stock, depository receipts, and securities convertible into common stock, such as warrants, rights, convertible bonds, debentures and convertible preferred stocks. Typically, a company is considered to be a "small capitalization" company if it has, at the time of investment, a market capitalization that is below $5 billion or in the range of the companies included in the MSCI World Ex U.S. Small Cap Index (which ranged from approximately $58.37 million to $7.95 billion as of December 31, 2015). The Fund will normally invest in companies located in at least three countries outside of the U.S. A company is considered to be located in a particular country if it: (i) is organized under the laws of the country; (ii) has securities which are principally traded on a stock exchange in the country; (iii) derives at least 50% of its revenues from goods produced or sold, investments made, or services performed in the country; or (iv) maintains at least 50% of its assets in the country. Although the Fund is not subject to any additional geographic requirement, the Fund expects that the majority of its investments will be in the developed markets of Canada, Western Europe, Asia and Australasia. The Fund may invest more than 25% of its net assets in securities of companies located in each of the United Kingdom and Japan. In order to gain additional exposure to the international, small capitalization market, the Fund may also invest in exchange traded funds ("ETFs"), whose underlying securities are issued by international small capitalization companies.

Investment Process: Epoch Investment Partners, Inc., the Fund's Subadvisor, invests primarily in companies that generate free cash flow and have managements that allocate it effectively to create shareholder value.

The security selection process focuses on free-cash-flow analytics as opposed to traditional accounting-based metrics. The Subadvisor seeks to identify companies with a consistent, straightforward ability to both generate free cash flow and to intelligently allocate it among internal reinvestment opportunities, acquisitions, dividends, share repurchases and/or debt reduction.

The Subadvisor may sell or reduce a position in a security when it believes its investment objectives have been met or when the security is deemed less attractive relative to another security on a return/risk basis. The Subadvisor may sell or reduce a position in a security if it sees the investment thesis failing to materialize.

Principal Risks

Loss of Money Risk: Before considering an investment in the Fund, you should understand that you could lose money.

Market Changes Risk: The value of the Fund's investments may fluctuate because of changes in the markets in which the Fund invests, which could cause the Fund to underperform other funds with similar objectives. Changes in these markets may be rapid and unpredictable. From time to time, markets may experience periods of stress for potentially prolonged periods that may result in (i) increased market volatility; (ii) reduced market liquidity; and (iii) increased redemptions. Such conditions may add significantly to the risk of volatility in the net asset value of the Fund's shares.

Portfolio Management Risk: The investment strategies, practices and risk analysis used by the Subadvisor may not produce the desired results. In addition, the Fund may not achieve its investment objective if the Subadvisor takes temporary positions in response to unusual or adverse market, economic or political conditions, or other unusual or abnormal circumstances.

Selection Risk: The investments selected by the Fund's Subadvisor may underperform the market or other investments.

Equity Securities Risk: Investments in common stocks and other equity securities are particularly subject to the risk of changing economic, stock market, industry and company conditions and the risks inherent in the portfolio managers' ability to anticipate such changes that can adversely affect the value of the Fund's holdings. Opportunity for greater gain often comes with greater risk of loss.

Depositary Receipts Risk: Investments in depositary receipts may entail the special risks of foreign investing, including currency exchange fluctuations, government regulations, and the potential for political and economic instability.

Small-Cap Stock Risk: Stocks of small capitalization companies may be subject to greater price volatility, significantly lower trading volumes, cyclical, static or moderate growth prospects, and greater spreads between bid and ask prices than stocks of larger companies. Small-capitalization companies may be more vulnerable to adverse business or market developments.

Foreign Securities Risk: Investments in foreign securities may be riskier than investments in U.S. securities. Differences between U.S. and foreign regulatory regimes and securities markets, including less stringent investor protections and disclosure standards of some foreign markets, less liquid trading markets and political and economic developments in foreign countries, may affect the value of the Fund's investments in foreign securities. Foreign securities may also subject the Fund's investments to changes in currency rates.

Liquidity and Valuation Risk: Securities purchased by the Fund may be illiquid at the time of purchase or liquid at the time of purchase and subsequently become illiquid due to, among other things, events relating to the issuer of the securities, market events, economic conditions, investor perceptions or lack of market participants. The lack of an active trading market may make it difficult to obtain an accurate price for a security. If market conditions or issuer specific developments make it difficult to value securities, the Fund may value these securities using more subjective methods, such as fair value pricing. In such cases, the value determined for a security could be different than the value realized upon such security's sale. As a result, an investor could pay more than the market value when buying Fund shares or receive less than the market value when selling Fund shares. This could affect the proceeds of any redemption or the number of shares an investor receives upon purchase. Liquidity risk may also refer to the risk that the Fund may not be able to pay redemption proceeds within the allowable time period because of unusual market conditions, unusually high volume of redemptions, or other reasons. To meet redemption requests or to raise cash to pursue other investment opportunities, the Fund may be forced to sell securities at an unfavorable time and/or under unfavorable conditions, which may adversely affect the Fund.

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Emerging Markets Risk: The risks related to investing in foreign securities are generally greater with respect to securities of companies that conduct their business activities in emerging markets or whose securities are traded principally in emerging markets. The risks of investing in emerging markets include the risks of illiquidity, increased price volatility, smaller market capitalizations, less government regulation, less extensive and less frequent accounting, financial and other reporting requirements, risk of loss resulting from problems in share registration and custody, substantial economic and political disruptions and the nationalization of foreign deposits or assets.

Convertible Securities Risk: Convertible securities may be subordinate to other securities. In part, the total return for a convertible security depends upon the performance of the underlying stock into which it can be converted. Also, issuers of convertible securities are often not as strong financially as those issuing securities with higher credit ratings, are more likely to encounter financial difficulties and typically are more vulnerable to changes in the economy, such as a recession or a sustained period of rising interest rates, which could affect their ability to make interest and principal payments. If an issuer stops making interest and/or principal payments, the Fund could lose its entire investment.

Exchange-Traded Fund Risk: The risks of owning an ETF generally reflect the risks of owning the underlying securities they are designed to track, although lack of liquidity in an ETF could result in it being more volatile than the underlying portfolio of securities. Disruptions in the markets for the securities underlying ETFs purchased or sold by the Fund could result in losses on the Fund's investment in ETFs. ETFs also have management fees that increase their costs versus the costs of owning the underlying securities directly.

Past Performance

The following bar chart and tables indicate some of the risks of investing in the Fund. The bar chart shows you how the Fund's calendar year performance has varied over the last ten years. Sales loads are not reflected in the bar chart. If they were, returns would be less than those shown. The average annual total returns table shows how the Fund's average annual total returns (before and after taxes) for the one,-five-and ten-year periods compare to those of a broad-based securities market index. The Fund has selected the MSCI World Ex U.S. Small Cap Indexas its primary benchmark. The MSCI World Ex U.S. Small Cap Index is composed of small capitalization stocks designed to measure equity performance in global developed markets, excluding the U.S.

Performance figures for Class I and Class A shares reflect the historical performance of the Institutional shares and Class P shares, respectively, of the Epoch International Small Cap Fund (the predecessor to the Fund, which was subject to a different fee structure, and for which Epoch Investment Partners, Inc. served as investment adviser) for periods prior to November 16, 2009. Performance data for the classes varies based on differences in their fee and expense structures. Class A shares (formerly Class P shares) were first offered on August 2, 2006. Performance figures for Class C and Investor Class shares, first offered November 16, 2009, reflect the historical performance of Class I shares through November 15, 2009, adjusted for differences in certain fees and expenses. Unadjusted, the performance shown for these newer share classes would likely have been different. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Please visit mainstayinvestments.com for more recent performance information.

Annual Returns, Class I Shares

(by calendar year 2006-2015)

Best Quarter
2Q/09	28.06	%
Worst Quarter
3Q/08	-26.68	%

Average Annual Total Returns (for the periods ended December 31, 2015)

	1 Year		5 Years		10 Years
Return Before Taxes
Class A	3.85	%	1.66	%	3.35	%*
Investor Class	3.63	%	1.47	%	4.68	%
Class C	7.86	%	1.87	%	4.61	%
Class I	10.10	%	3.06	%	5.73	%
Return After Taxes on Distributions
Class I	9.64	%	2.86	%	4.94	%
Return After Taxes on Distributions and Sale of Fund Shares
Class I	6.39	%	2.54	%	4.59	%
MSCI World Ex U.S. Small Cap Index (reflects no deductions for fees, expenses, or taxes)	5.46	%	4.39	%	4.09	%

* Reflects performance from August 2, 2006.

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After-tax returns are calculated using the highest individual federal marginal income tax rates in effect at the time of each distribution or capital gain or upon the sale of fund shares, and do not reflect the impact of state and local taxes. In some cases, the return after taxes may exceed the return before taxes due to an assumed tax benefit from any losses on a sale of shares at the end of the measurement period. Actual after-tax returns depend on your tax situation and may differ from those shown. After-tax returns are not relevant if you hold your shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns shown are for Class I shares. After-tax returns for the other share classes may vary.

Management

New York Life Investment Management LLC serves as the Fund's Manager. Epoch Investment Partners, Inc. serves as the Fund's Subadvisor.

Subadvisor	Portfolio Managers	Service Date
Epoch Investment Partners, Inc.	Eric Citerne, Managing Director	Since 2011
	Michael Welhoelter, Managing Director	Since 2009
	John Morgan, Managing Director	Since 2014

How to Purchase and Sell Shares

You may purchase or sell shares of the Fund on any day the Fund is open for business by contacting your financial adviser or financial intermediary firm, or by contacting the Fund by telephone at 800-MAINSTAY (624-6782), by mail at MainStay Funds, P.O. Box 8401, Boston, MA 02266-8401 or by accessing our website at mainstayinvestments.com. Generally, an initial investment minimum of $2,500 applies if you invest in Investor Class or Class C shares, $25,000 for Class A shares and $5,000,000 for individual investors in Class I shares investing directly (i) with the Fund; or (ii) through certain private banks and trust companies that have an agreement with NYLIFE Distributors LLC, the Fund’s principal underwriter and distributor, or its affiliates. A subsequent investment minimum of $50 applies to investments in Investor Class and Class C shares. These initial investment minimum and subsequent purchase amounts also apply to Investor Class and Class C shares purchased through AutoInvest, MainStay's systematic investment plan. Institutional shareholders in Class I shares have no initial or subsequent investment minimums.

Tax Information

The Fund's distributions are generally taxable to you as ordinary income, capital gains, or a combination of the two, unless you are investing through a tax-deferred arrangement, such as a 401(k) plan or an individual retirement account.

Compensation to Financial Intermediary Firms

If you purchase Fund shares through a financial intermediary firm (such as a broker/dealer or bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the financial intermediary firm or your financial adviser to recommend the Fund over another investment. Ask your financial adviser or visit your financial intermediary firm's website for more information. For additional information about compensation to financial intermediaries, please see the section entitled "Compensation to Financial Intermediary Firms" in the "Shareholder Guide" section starting on page 106 of the Prospectus.

To Statutory ProspectusTo Statement of Additional Information

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