Mail forwarding extends for different lengths of time depending on the type of mail. And each type is handled a little differently.
First-class and priority mail are forwarded for 12 months at no charge, as long as the sender did not place a non-forwarding endorsement, such as "do not forward", on the mail piece. During months 13-18, the mail is returned to sender with your new address. After 18 months, the mail is simply returned to the sender.
The same forwarding time period and return treatment applies to express mail. It also receives the same expedited treatment as before; however, the delivery guarantee is void when it is forwarded.
Your magazines and newspapers will be forwarded for 60 days at no charge. After 60 days, the computerized forwarding system will handle the periodical based on the type of change of address on file. If you filed a temporary change of address, your periodicals will be disposed of after 60 days. If you have a permanent change of address on file, they will be returned to the sender with your new address.
Just about the time you start getting settled in your new home, after about seven to 10 postal business days, your mail will start arriving at your new address. If it doesn't, it's time to call 1-800-ASK-USPS.