What do I do if I lost my W2??

The first thing that I would suggest is to contact your employer. Sometimes for some businesses, the W-2's are even available online.

Yes the company you worked for can just reprint a new one, and as noted some are online.

I had the same situation. I either never got or misplaced one of my W2s. I called the payroll department and they said they would reissue it immediately.

I got a copy of it, thanks for all the help guys.

Noted!