OK, I don't know how many New York Subway cards I have that have expired, so here are two solutions:
- If you have an expired MetroCard with money in it, take it to the subway station and they will give you a new card for free.
- EasyPay. If you don't get there often enough, use EasyPay so that you have a subway MetroCard tied to automatic credit card replenishment. As an aside, use a card like Chase Sapphire Reserve with 3x bonuses for transportation.