X0101 EFFECT 33 LIVE 2009-11-10 12:15:00

N-1A

0001469192 MAINSTAY FUNDS TRUST 333-160918 S000026784 MainStay Epoch U.S. Equity Fund C000080506 Investor Class S000026784 MainStay Epoch U.S. Equity Fund C000080507 Class A S000026784 MainStay Epoch U.S. Equity Fund C000080508 Class C S000026784 MainStay Epoch U.S. Equity Fund C000080509 Class I S000026785 MainStay Epoch Global Choice Fund C000080510 Investor Class S000026785 MainStay Epoch Global Choice Fund C000080511 Class A S000026785 MainStay Epoch Global Choice Fund C000080512 Class C S000026785 MainStay Epoch Global Choice Fund C000080513 Class I S000026786 MainStay Epoch Global Equity Yield Fund C000080514 Class A S000026786 MainStay Epoch Global Equity Yield Fund C000080515 Class C S000026786 MainStay Epoch Global Equity Yield Fund C000080516 Class I S000026786 MainStay Epoch Global Equity Yield Fund C000080517 Investor Class S000026787 MainStay Epoch International Small Cap Fund C000080518 Investor Class S000026787 MainStay Epoch International Small Cap Fund C000080519 Class A S000026787 MainStay Epoch International Small Cap Fund C000080520 Class C S000026787 MainStay Epoch International Small Cap Fund C000080521 Class I