This API allows you to programmatically retrieve LOINC’s primary release artifact.

Authentication is required and described separately.

Base URL

https://loinc.regenstrief.org/api/v1

Endpoints

GET /Loinc

This endpoint returns information on the current version of LOINC by default. The response will include the version, release date, number of LOINCs, and download URL.

You may also pass version as a parameter to get details on that specific LOINC version string. Consider the following request using cURL. (Note the authorization header has been excluded from the example.)

curl -X GET 'https://loinc.regenstrief.org/api/v1/Loinc?version=2.80'

The response body should be the following:

{
  "version": "2.80",
  "releaseDate": "2025-02-26T00:00:00",
  "relmaVersion": "7.13",
  "numberOfLoincs": 104672,
  "maxLoinc": "107378-2",
  "downloadUrl": "https://loinc.regenstrief.org/api/v1/Loinc/Download?version=2.80",
  "downloadMD5Hash": "e4c5f4ec8844d79abeed07a0e3493d1a"
}

Should the version included as a parameter not exist, a 404 (Not Found) error will be returned.

GET /Loinc/All

This endpoint will provide the same metadata as above but for every past release of LOINC. There are no available parameters on this endpoint.

GET /Loinc/Download

This endpoint will provide the LOINC release file (zip) contents as an attachment to the response body.

By default this will be the current version. You may pass version as a parameter for the specified version, e.g., GET /Loinc/Download?version=2.79. Should the version not exist, a 404 (Not Found) error will be returned.

Best practices

If your use case is to poll this API for a new version of LOINC, we recommend using the /Loinc endpoint. You can then compare the version string or releaseDate provided to ones known by your system. If different/newer, use the provided downloadUrl to retrieve the file and the downloadMD5Hash to verify the file’s integrity.

We discourage polling this API more than once daily.