X0101 EFFECT 33 LIVE 2022-02-28 0001741773-22-000403 485APOS 0001469192 MAINSTAY FUNDS TRUST 333-160918 S000028542 MainStay WMC International Research Equity Fund C000087393 Investor Class S000028542 MainStay WMC International Research Equity Fund C000087394 Class A S000028542 MainStay WMC International Research Equity Fund C000087395 Class C S000028542 MainStay WMC International Research Equity Fund C000087396 Class I S000028542 MainStay WMC International Research Equity Fund C000185938 Class R6 S000028542 MainStay WMC International Research Equity Fund C000221669 SIMPLE Class S000036714 MainStay Balanced Fund C000112258 Class A S000036714 MainStay Balanced Fund C000112259 Class B S000036714 MainStay Balanced Fund C000112260 Class C S000036714 MainStay Balanced Fund C000112261 Class I S000036714 MainStay Balanced Fund C000112262 Class R1 S000036714 MainStay Balanced Fund C000112263 Class R2 S000036714 MainStay Balanced Fund C000112264 Class R3 S000036714 MainStay Balanced Fund C000112265 Investor Class S000036714 MainStay Balanced Fund C000185940 Class R6 S000036714 MainStay Balanced Fund C000221670 SIMPLE Class S000036715 MainStay WMC Small Companies Fund C000112266 Class B S000036715 MainStay WMC Small Companies Fund C000112267 Class C S000036715 MainStay WMC Small Companies Fund C000112268 Class I S000036715 MainStay WMC Small Companies Fund C000112269 Investor Class S000036715 MainStay WMC Small Companies Fund C000112270 Class A S000036715 MainStay WMC Small Companies Fund C000118993 Class R1 S000036715 MainStay WMC Small Companies Fund C000118994 Class R2 S000036715 MainStay WMC Small Companies Fund C000166845 Class R3 S000036715 MainStay WMC Small Companies Fund C000185942 Class R6 S000036715 MainStay WMC Small Companies Fund C000221671 SIMPLE Class S000039358 MainStay WMC Growth Fund C000121293 Class A S000039358 MainStay WMC Growth Fund C000121294 Class B S000039358 MainStay WMC Growth Fund C000121295 Class C S000039358 MainStay WMC Growth Fund C000121296 Class I S000039358 MainStay WMC Growth Fund C000121297 Class R2 S000039358 MainStay WMC Growth Fund C000121298 Investor Class S000039358 MainStay WMC Growth Fund C000185948 Class R6 S000039358 MainStay WMC Growth Fund C000221675 SIMPLE Class