I received my social security statement and my income for the cuurent year was not correct. I had two separate W-2s from the same employer (changed payroll co.s), one W-2was not reported. My boss is a little on the "shady" side. He has failed to pay health insurance premiums causing lapses and failed to forward 401k contributions in a timely manner. I believe he now is not reporting our full income to avoid paying social security taxes. I guess my question is " Is there a grace period for reporting and maybe he has just not done this? Or should I just report this to the IRS?

Report him to the IRS and the 401k

Talk to your boss and find out why there is a difference.