[6][7] Its original administrator was Jon Postel of the Information Sciences Institute (ISI) at the University of Southern California (USC).

In July 1997, Postel instituted a "50/500 rule" that limited each delegated manager to 500 localities maximum, 50 in a given state.

In September 1998, the United States Postal Service proposed funding the operations in order to assume control of .us, as part of a plan to diversify away from postage revenue.

[11] On October 1, 1998, the NSF transferred oversight of the .us domain to the National Telecommunications and Information Administration (NTIA) of the United States Department of Commerce.

[17] Neustar's contract was renewed by the National Telecommunications and Information Administration (NTIA) in 2007 and most recently in 2014.

[10][18] On March 31, 2019, the .us registry made it clear that under its Acceptable Use Policy it would not allow the sale of opioids through the .us top level domain.

Though the locality namespace is most commonly used for government entities, it is also open to registrations by private businesses and individuals.

As the delegated managers are expected to receive requests directly from registrants, few if any domain name registrars serve this space, possibly contributing to its lower visibility and utilization.

[22] According to a 2013 survey of 539 delegated managers, 282 were state or local government agencies, while 98 were private individuals and 85 were commercial Internet service providers.

A two-letter second-level domain is formally reserved for each U.S. state, federal territory, and the District of Columbia.

A state's main government portal is usually found at the third-level domain state.state.us, which is reserved for this purpose.

Since April 2003, the .edu top-level domain has been available as an alternative for community colleges, technical and vocational schools, and other tertiary educational institutions that might have previously used the .cc or .tec affinity namespaces.

The general public could register third-level domains under .kids.us for educational content that met strict requirements, including conformance to the Children's Online Privacy Protection Act and adherence to Children's Advertising Review Unit standards.

On July 27, 2012, in response to declining usage and a petition by Neustar the previous year, the NTIA suspended .kids.us registrations.