The 2022AA release of the Unified Medical Language System® (UMLS) Knowledge Sources is available for download as of May 2, 2022.

The available downloads are:

• Full Release (UMLS Metathesaurus, Semantic Network, Specialist Lexicon and Lexical Tools, database load scripts, and MetamorphoSys for customizing your UMLS subset and browsing the data)
• UMLS Metathesaurus Files (complete Metathesaurus data without any customization)
• MRCONSO.RRF file (most widely used Metathesaurus file)

UMLS REST API authentication is changing. You can now authenticate by simply appending an apiKey parameter to your request, for example:

https://uts-ws.nlm.nih.gov/rest/content/current/CUI/C0155502/atoms?apiKey={{YOUR_API_KEY}}

Authentication via ticket-granting tickets (TGTs) and service tickets is deprecated, but we will continue to accept API authentication via this method until May 2023.

Metathesaurus

The 2022AA Metathesaurus contains approximately 4.55 million concepts and 16.9 million unique concept names from 222 source vocabularies.

Two new LNC translations:

• LNC-ES-MX (LOINC Linguistic Variant - Spanish, Mexico)
• LNC-PL-PL (LOINC Linguistic Variant - Polish, Poland)

78 English sources and 34 translation sources were updated. These include MeSH^®, MedDRA, RxNorm, and SNOMED CT^® (English and Spanish). For detailed information on changes in this version of the Metathesaurus, see the Updated Sources (Expanded) section. Additional release statistics may be found in the Statistics section.

SPECIALIST Lexicon and Lexical Tools

• The release includes the updated SPECIALIST Lexicon (2022 Release).
• The release includes the updated Lexical Tools (2022 Release) which integrate data from the SPECIALIST Lexicon, 2022 Release. The Lexical Tools include the Full and Lite versions of lvg.2022.
• The Metathesaurus index files were processed using the updated lvg files.

MetamorphoSys

• The full release requires 33.5 GB of disk space.

Reported bugs may be viewed on the Release Notes and Bugs web page.

MetamorphoSys can generate custom load scripts for MySQL, Oracle, or Microsoft Access when creating a Metathesaurus subset or installing the Semantic Network. Instructions are available on the UMLS Load Scripts homepage.

Release Information

To access the UMLS Release files, you must have an active UMLS Metathesaurus® License and a valid UTS account. You will be prompted to authenticate with an identity provider with the UTS when downloading the files.

UMLS Learning Resources

2022AA Source Release Documentation web pages are available.

Additional information regarding the UMLS is available on the UMLS homepage. New users are encouraged to take the UMLS Basics Tutorial and to explore the UMLS Quick Start Guide, and other training materials.

UMLS Terminology Services (UTS)

The UTS Metathesaurus Browser and the UTS REST API include the updated release.

UMLS REST API authentication is changing. You can now authenticate by simply appending an apiKey parameter to your request, for example:

https://uts-ws.nlm.nih.gov/rest/content/current/CUI/C0155502/atoms?apiKey={{YOUR_API_KEY}}

Authentication via ticket-granting tickets (TGTs) and service tickets is deprecated, but we will continue to accept API authentication via this method until May 2023.

UMLS User Contributions

UMLS users have extended the functionality of the UMLS in a variety of ways by developing APIs, automation scripts, and natural language processing tools. You can find a list of these resources on the UMLS Community web page.

Want to add your tool? Send a request to the NLM Help Desk with the subject line: "UMLS Community."

Be sure to include a link to your source code so that other UMLS users can adapt your tool. We are especially interested in:

• Database load scripts
• Transformation scripts that convert UMLS data into other formats (for example, RDF or JSON)
• Scripts that automate any aspect of UMLS installation
• Applications that leverage UMLS in the processing of text