Every year,the General Services Administration (GSA) establishes per diem rates for government employees in the 48 states in the continental U.S. and the District of Columbia ("CONUS" rates); in areas outside the continental United States (Hawaii, Puerto Rico and U.S. possessions ("OCONUS" rates); and in foreign countries.

The IRS says that private employers may use these "per diem" rates as a record keeping shortcut to reimburse employees for business travel with no hassles.