Anyone have a suggestion where to look for grips for the MP15? I've gone to S&W's site and several others, but when I search for grips they pull up all kinds of accessories having nothing to do with grips. Feeling pretty dumb.
If you mean the grip that your trigger hand would use, pretty much any Magpul grip would work. Otherwise, look for anything dedicated to AR15's and you're safe. Some are rubber and others plastic. It's up to you what you want to hold on to. Here's for the back (trigger) end:
Short answer: The M&P 15-22 is compatible with almost all standard mil-spec AR-15 pistol grips. Just watch out for both springs when removing the grip, they tend to go flying.