The expiration of a money order can vary by issuer, but most are valid for up to one year from the date of purchase. Some money orders may have shorter or longer validity periods, and it’s important to check the specific terms and conditions of the money order issuer. Unclaimed money orders after a certain period may be subject to escheatment laws, meaning the funds could be turned over to the state. It’s advisable to cash or use a money order as soon as possible to avoid any potential issues.