A bank has no obligation to cash a person's check that is over six months old, according to Cornell University Law School. The bank can choose to accept the check in good faith. In some cases, the bank might wish to speak with the person who wrote the check before accepting it.
A person who wishes to cash an expired check might choose to ask the issuer for a new one or speak directly with a teller at the bank. The teller will let the depositing party know if a problem could arise with the transaction because of the age of the check, as different banks have different policies.
To have an expired government check reissued, the person should contact the paying agency directly to explain the situation. As long the person has not cashed the check, the paying agency should send out a replacement.