CMS Interoperability API
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Getting Started

Provider Directory API

The Provider Directory API publishes our plan network directory — organizations, practitioners, locations, and their network affiliations — as public FHIR data. No authorization required.

1 Make a Request

Every endpoint is a plain, unauthenticated GET request — no Authorization header, token, or registered app is needed. 

GET https://cms-api.wasatch.org/directory/fhir/r4/Practitioner
Accept: application/fhir+json

Responses are returned as application/fhir+json — a FHIR R4 Bundle for search results, or a single resource for a direct /{Resource}/{id} lookup.

2 Search and Paginate

Each resource supports its own set of search parameters — see the API Reference for the full list per resource. Every search endpoint also supports:

  • _count — page size (default 20, max 100)
  • _offset — number of results to skip
GET https://cms-api.wasatch.org/directory/fhir/r4/Practitioner?name=Bennett&_count=10&_offset=0
3 Handle Not-Found Responses

A direct lookup for an id that doesn't exist returns a FHIR OperationOutcome with a 404 status: 

{
  "resourceType": "OperationOutcome",
  "issue": [{
    "severity": "error",
    "code": "not-found",
    "diagnostics": "Practitioner/999999 not found."
  }]
}
Next Steps