What a ZIP lookup can—and cannot—tell you

The GSA ZIP files connect postal codes with per diem destinations and monthly rates. They do not replace the locality definitions. In the included FY2027 file, 40,426 distinct ZIP values appear in 42,358 rows, and 1,839 values connect to more than one rate locality.

We show all different matching localities rather than selecting the first or highest rate. The importer compares every row’s twelve lodging values and M&IE amount against the master rate file before accepting the match.

Enter all five digits: 00501 is different from 501. The search box treats a ZIP as text and preserves leading zeroes. An incomplete number, ZIP+4 input or a value absent from the official file does not silently become a standard-rate destination.

The file is not presented as a current USPS address validator. A value appearing in the source proves only that GSA included it in that edition. Use the issuing authority to resolve an unusual or disputed entry.

Each fiscal year has its own lookup. FY2026 includes 13 rows without a state value; those omissions are retained and disclosed, not filled from an unrelated address list. FY2027 has no missing state values in the included snapshot.

If the search returns more than one locality, establish the work address and read the county boundaries. If it returns nothing, search by county and consult GSA. Neither case justifies an automatic rate assignment.