2017 forester 2.5i push to start key fob stopped working.

Depends. Why would it require reprogramming? If it's a DIFFERENT fob from your car you have to beg a dealer to program it to your car dash's receiver for 1/2 hr labor charge. Many dealers won't do it as they'd rather sell you an entire cut key-fob.

Hang on, Ed. Doesn't work with modern Subarus, which require presentation live to a dealer to program fobs to the in-dash receivers. Again, there's usually a half-hour labor charge for up to 4 additional fobs at one session.

I meant 4 TOTAL fobs at one session.