MainStay Money Market Fund  Class A: MMAXX | Class B: MKMXX | Class C: MSCXX | Class INV: MKTXX | Class SI: MIPXX

BEFORE YOU INVEST

You could lose money by investing in the Fund. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. The Fund may impose a fee upon sale of your shares or temporarily suspend your ability to sell shares if the Fund's liquidity falls below required minimums of market conditions or other factors. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund's sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time.


There are no sales charges applied when buying or redeeming shares in MainStay Money Market Fund. However, if you exchange Class A shares or Investor Class shares of MainStay Money Market Fund for Class A shares or Investor Class shares of another MainStay Fund, the applicable sales charge will apply unless you’ve already paid the sales charge on those shares; or, if you exchange Class B shares of MainStay Money Market Fund for Class B shares of another MainStay Fund and redeem within six years of the original purchase, or if you exchange Class C shares of MainStay Money Market Fund for Class C shares of another MainStay Fund and redeem within one year of the original purchase, the applicable contingent deferred sales charge will be assessed.


Standard Deviation measures how widely dispersed a fund's returns have been over a specified period of time. A high standard deviation indicates that the range is wide, implying greater potential for volatility.


Weighted Average Life measures the maturity of the fund's investments without regard to a security's interest rate reset dates.


Weighted Average Maturity is an average of the maturities of all securities held in the Fund's portfolio, weighted by each security's percentage of net assets.


New York Life Investment Management LLC engages the services of federally registered advisors. Fixed Income Investors, a division of NYL Investors LLC, is an affiliate with New York Life.