It would only do that if your medicare tax on all W-2's was more than the maximum and you got a credit for the excess. If you are filing Married Jointly, did both spouses has W-2 income? You might have entered both W-2's for the same spouse by mistake and the medicare tax was added together.
**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.**
