NLM logo

UMLS API Technical Documentation

We welcome your feedback on our customer service form. Please use "UMLS REST API feedback" in your subject line.

Check out the Postman sample collection to help you get started using the UMLS REST API.

API Terms of Service

Automating UMLS Terminology Services Downloads

This documentation will help you to:

  1. Get the latest release files for RxNorm, SNOMED CT, and UMLS (Release API)

  2. Download release files automatically (Download API)

Release API

This API endpoint provides a list of releases for RxNorm, SNOMED CT, and UMLS. You can use this endpoint to get the latest release or to obtain past releases.

Base URL: https://uts-ws.nlm.nih.gov/releases

Parameter name Required? Y/N Description
releaseType N You can find a list of releaseTypes here: https://uts-ws.nlm.nih.gov/releases
current N Defaults to false. Set to current=true to get only the current release.

RxNorm

Release Parameter
RxNorm Full Monthly Release releaseType=rxnorm-full-monthly-release
RxNorm Weekly Updates releaseType=rxnorm-weekly-updates
RxNorm Prescribable Content Monthly Release releaseType=rxnorm-prescribable-content-monthly-release
RxNorm Prescribable Content Weekly Updates releaseType=rxnorm-prescribable-content-weekly-updates
RxNav-in-a-Box releaseType=rxnav-in-a-box

SNOMED CT

Release Parameter
SNOMED CT US Edition releaseType=snomed-ct-us-edition
SNOMED CT US Edition Transitive Closure Resources releaseType=snomed-ct-us-edition-transitive-closure-resources
SNOMED CT International Edition releaseType=snomed-ct-international-edition
SNOMED CT CORE Problem List Subset releaseType=snomed-ct-core-problem-list-subset
SNOMED CT to ICD-10-CM Mapping Resources releaseType=snomed-ct-to-icd-10-cm-mapping-resources
SNOMED CT Spanish Edition releaseType=snomed-ct-spanish-edition

UMLS

Release Parameter
UMLS Metathesaurus Full Subset releaseType=umls-metathesaurus-full-subset
UMLS Metathesaurus MRCONSO File releaseType=umls-metathesaurus-mrconso-file
UMLS Full Release releaseType=umls-full-release

Download API

This API endpoint allows you to download RxNorm, SNOMED CT, or UMLS releases by providing the download URL and your API key.

Base URL: https://uts-ws.nlm.nih.gov/download

Parameter name Required? Y/N Description
url Y Provide the URL for the release you wish to download.
apiKey Y An API key is required for each call to the API. Visit your UTS profile to obtain your API key.

Examples

Download RxNorm Weekly Updates

https://uts-ws.nlm.nih.gov/download
?url=https://download.nlm.nih.gov/umls/kss/rxnorm/RxNorm_weekly_10052022.zip
&apiKey=YOUR_API_KEY

curl example:

curl "https://uts-ws.nlm.nih.gov/download?url=https://download.nlm.nih.gov/umls/kss/rxnorm/RxNorm_weekly_10052022.zip&apiKey=YOUR_API_KEY" -o RxNorm_weekly_10052022.zip

Download the US Edition of SNOMED CT

https://uts-ws.nlm.nih.gov/download
?url=https://download.nlm.nih.gov/mlb/utsauth/USExt/SnomedCT_USEditionRF2_PRODUCTION_20220901T120000Z.zip
&apiKey=YOUR_API_KEY

curl example:

curl "https://uts-ws.nlm.nih.gov/download?url=https://download.nlm.nih.gov/mlb/utsauth/USExt/SnomedCT_USEditionRF2_PRODUCTION_20220901T120000Z.zip&apiKey=YOUR_API_KEY" -o SnomedCT_USEditionRF2_PRODUCTION_20220901T120000Z.zip

Download the UMLS Release

https://uts-ws.nlm.nih.gov/download
?url=https://download.nlm.nih.gov/umls/kss/2022AA/umls-2022AA-full.zip
&apiKey=YOUR_API_KEY

curl example:

curl "https://uts-ws.nlm.nih.gov/download?url=https://download.nlm.nih.gov/umls/kss/2022AA/umls-2022AA-full.zip&apiKey=YOUR_API_KEY" -o umls-2022AA-full.zip