CMS ZIP code to carrier locality files, release by release
The quarterly crosswalk mapping every 5-digit ZIP code to the Medicare payment locality whose GPCIs price claims from that ZIP.
CMS updates this file quarterly — January, April, July, and October — and occasionally re-posts a quarter mid-stream to fix errors. Each version we ingested is preserved below as its own immutable release.
CMS reorganizes its site often and direct file links break. If a download link below stops working, every release remains available from the official CMS ZIP-to-locality crosswalk page.
2026
In effect July 1 – September 30, 2026 (Q3 2026 on this site).
Our methodology documents how every file is parsed, versioned, and verified@if ($isPfs) — the changes pages show the quarter-over-quarter rate movement each release caused@endif.