Unified Medical Language System (UMLS)

2004AC Metathesaurus now available to download from the UMLSKS. Includes the new RRF Browser (beta) for viewing your subsets. ••• New to the UMLS? Register now.

	About the UMLS Resources
	Metathesaurus; Semantic Network; SPECIALIST Lexicon and lexical programs; MetamorphoSys

	Accessing UMLS Knowledge Sources
	Metathesaurus license; Semantic Network; SPECIALIST Lexicon; DVD

	Knowledge Source Server
	Download files; searching; additional tools and resources

	Documentation

	Help
	Training; contact us; FAQs; listserv

• SNOMED CT
• LOINC
• RxNorm
• MeSH
• List of Sources
• Source FAQs

• Metathesaurus License
• Tools
• Learning Resources

• Archives

NLM's Unified Medical Language System (UMLS) project develops and distributes multi-purpose, electronic "Knowledge Sources" and associated lexical programs for system developers. Researchers will find the UMLS products useful in investigating knowledge representation and retrieval questions.

Last updated: 27 October 2004
First published: 01 January 1999
Metadata| Permanence level: Permanence Not Guaranteed