If you are a foreign national who works in the U.S. but is not subject to Social Security or Medicare taxes due to a treaty with your home country, you may request a refund of your Social Security and Medicare taxes from your employer if it mistakenly withheld these taxes from your wages on Form W-2.

If your employer does not refund the full amount, you may submit Form 843 to the IRS to claim the balance. You should attach the following documents to Form 843:

• A copy of your Form W-2 to prove the amount of social security and Medicare taxes withheld.
• A copy of your visa.
• Form I-94 (or other documentation showing your dates of arrival or departure).
• If you have an F-1 or J-1 visa, documentation showing permission to work in the United States
• If you are engaged in optional practical training or employment due to severe economic necessity, documentation showing permission to work in the United States.
• A statement from your employer indicating the amount of the reimbursement your employer provided and the amount of the credit or refund your employer claimed or you authorized your employer to claim. If you cannot obtain this statement from your employer, you must provide this information on your own statement and explain why you are not attaching a statement from your employer or on Form 8316 claiming your employer will not issue the refund.
• If you were exempt from social security and Medicare tax for only part of the year, pay statements showing the tax paid during the period you were exempt.

For additional information, please refer to the Refund of Taxes Withheld in Error topic in IRS Publication 519 U.S. Tax Guide for Aliens.