The United States Postal Service (USPS), also known as the Post Office, U.S. Mail, or Postal Service, is an independent agency of the executive branch of the United States federal government responsible for providing postal service in the United States, its insular areas, and its associated states. It is one of the few government agencies explicitly authorized by the Constitution of the United States. As of 2023, the USPS has 525,469 career employees and 114,623 non-career employees.

The Compacts of Free Association (COFA) are international agreements establishing and governing the relationships of free association between the United States and the three Pacific Island sovereign states of the Federated States of Micronesia (FSM), the Republic of the Marshall Islands (RMI), and the Republic of Palau. As a result, these countries are sometimes known as the Freely Associated States (FASs). All three agreements next expire in 2043.