You usually have a year to cash your Federal refund check from the date which it was issued. If your federal tax refund check issued by the U.S. Department of the Treasury expires, it can be replaced so long as the original was never cashed. In that instance you would contact the IRS, which issues federal tax return checks, at 1-800-829-1040. They will send you a claim form you must fill out before a replacement check can be issued.
State refund check expiration dates may vary, here is an FAQ with instructions on how to contact your State Department of Revenue to inquire:
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