It sounds like it might be a corrected W-2 that they only changed the boxes that changed from the original W-2. If that is the case and the SS and Medicare are different from the original W-2 then you would enter the information from the original W-2 and replace the SS & MC with the new updated information.
The employer should have issued a total new W-2C (corrected) to totally replace the original but some employers only send the boxes that changed and expect you to update only those boxes. Check with your employer.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
