Turbo tax says my W2 withheld too much social security. My employer said they did not calculate it wrong it's at 7.7%. Why is turbo tax giving me this error?

The Social Security and Medicare tax rate combined is 7.65% if your employer withheld 7.7% it is a little higher than the actual rate.  If it was withheld at a higher rate then any excess will calculate and show as a credit on your tax return.

Please double check your entries on your W-2 to make sure they are accurate.  But if the employer withheld 7.7% that is actually higher than the amount they are required to withhold.

Also check to make sure if you are Married Filing Joint that your W-2 information is showing the correct person so that the program does not calculate excess Social Security tax incorrectly.

Click on this link for more information about excess Social Security Tax.