If you had federal tax withheld throughout the year and the Federal Withheld boxes on your W-2 are blank, contact your employer first. Check your W-4 to make sure you are not marked as "exempt," and bring copies of your pay stubs that indicate the amount of federal tax withheld. Your employer can submit a form W-2C to the Social Security Administration to correct the mistake on your W-2. If you realize your W-4 marks you "exempt" from federal withholding and this is not the case, file a new form with your employer.
