Get the file from CMS Copy link
Direct download: Zip-Code-to-Carrier-Locality.zip
SHA-256 of the file we ingested: 315d43da4c58ab7a6971bcd89d4ec0c83993d11b7d1cda9d653ea2222c1a67fa
Direct CMS links break when cms.gov reorganizes. The stable fallback is the official CMS ZIP-to-locality crosswalk page.
Files inside this release Copy link
These are the member files we parsed, as recorded when we loaded them. Row counts and checksums let anyone verify our copy against CMS's. Where the name is a link, it downloads the exact bytes we parsed, straight out of the CMS zip—except the relative value file, marked scrubbed below, where we remove the AMA-copyrighted DESCRIPTION column before publishing and leave everything else untouched.
| File | What it is | Rows |
|---|---|---|
|
ZIP5_JAN18.txt
3.4 MB
SHA-256 0a6f147b80f1…
|
ZIP5—the ZIP-to-locality crosswalk | 42,939 |
What the columns mean Copy link
CMS publishes these files with minimal documentation, and both the column names and their order drift between releases—which is why we parse by header name, never by position. Any column position shown here is the one we recorded when parsing this release.
ZIP5—the ZIP-to-locality crosswalk
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One row per 5-digit ZIP code, mapping it to the MAC and payment locality whose GPCIs price claims from that ZIP. This is the file that turns "what does Medicare pay here?" into a specific locality's rates.
Open ZIP5_JAN18.txt (3.4 MB)| Column | What it means |
|---|---|
| State | Two-letter state or territory. |
| ZIP code | The 5-digit ZIP being mapped. |
| Carrier | The MAC that processes claims for this ZIP. |
| Locality | The payment locality code the ZIP prices under. |
| Rural indicator | Blank for urban, R for rural, B for super-rural—used by the ambulance fee schedule's rural bonuses. |
| Plus-4 flag | 1 when the ZIP spans more than one locality, meaning the full ZIP+4 is needed to price precisely. |
Where this release is used on this site Copy link
This crosswalk powers the ZIP-code lookups on our locality pages and the per-ZIP estimates on code pages. Ingested Aug 10, 2026. See how the whole process works in our methodology.