You can't pay too much on Medicare--you pay 1.45% no matter how much you make.
a.) had more than 1.45% tax withheld for Medicare from your wages. You'll have to go to your employer to have that fixed.
b.) had more than 6.2% Social Security tax withhold. The upper limit is $127,200 which means the max is $7,886.40.
You'll see the amount that you paid over that on line 71 of your Form 1040. To see:
1. Go to Tax Tools on the left-hand side.
2. Go to Tools.
3. Go to View Tax Summary.
4. Click Preview my 1040 from the left-hand side.