First, please check the delivery standard for the mail class of your domestic item. You can find the mail class by entering the US Mail Service Tracking number and looking up "Product Information.". Then compare your mail class and progress to what is found in the Mail Delivery Standards chart below.
Delivery time varies from one class of mail to another. It may be possible that the mailpiece is still in transit and is not lost or delayed depending on what class of mail is being used and how long ago it was mailed. The following chart outlines the delivery standards for various mail classes and indicates how long you should wait before you contact customer assistance with a concern.