Others may have additional thoughts on this, but one thing you MUST do is have your employer issue a corrected W-2 for every year that the wrong SSN was on your W-2. Those W-2's go not only to the IRS but to Social Security, so that your earnings are credited toward your future Social Security benefits. You need for those records to be accurate. And although your tax refunds came to you all right for a couple of tax returns, that incorrect W-2 could still come back to haunt you if the IRS catches it later. Get the employer to correct it, and give copies of the corrected W-2 to you, copies to the Social Security Administration, and the IRS.