This is what you need to do:
If your attempts to have an incorrect Form W-2 (PDF) corrected by your employer are unsuccessful and it is after February 15th, contact the IRS toll-free at - 800 - 829 - 1040.
An IRS representative can initiate a Form W-2 (PDF) complaint. A letter will be sent to the employer requesting that they furnish a corrected Form W-2 to you within ten days. The letter advises the employer to their responsibilities to provide a correct Form W-2 (PDF) and of the penalties to do so.
You will be sent a letter that provides instructions and Form 4852 (PDF), Substitute W-2 and Tax Statement, or Form 1099-R, Distributions from Pensions, Annunities, Retirement or Profit-Sharing Plans, IRAs, Insurance Contracts, etc. The Form 4852 may be used in the event that the employer does not provide you with the corrected Form W-2 in time to file your tax return.
When you call the IRS or visit an IRS Taxpayer Assistance Center (TAC), please have the following information available:
Your employer's name and complete address, including zip code, employer identification number (if known - see prior year's Form W-2 (PDF) if you worked same employer), and telephone number, your name, address, including zip code, social security number, and telephone number; and an estimate of the wages you earned, the federal income tax withheld, and the period you worked employer. The estimate should be based on year-to-date information from your final pay stub or leave-and-earnings statement, if possible.
If you file your return and attach Form 4852 (PDF) to support the withholding amount claimed instead of a Form W-2 (PDF), your refund can be delayed while the information you gave is verified.
If you receive a Form W-2 (PDF) after you file your return and it does not agree with the income or withheld tax you reported on your status, file an amended return on Form 1040X (PDF), Amended U.S. Individual Income Tax Return.
Form 4852 (PDF), Substitute W-2
Tax Topic 154, Form W-2 - what to do if not received
Tax Topic 308, Amended Returns
Form 1040X (PDF), Amended U.S. Individual Income Tax Return
This is from the IRS website at - http://www.irs.gov/faqs/faq/0,,id=199593,00.html