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Unified Medical Language System® (UMLS®)

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UMLS Knowledge Sources: File Downloads

Release Information
MetamorphoSys Installation Help

2023AB UMLS Metathesaurus Precomputed Subsets

Ready-to-use subsets of the UMLS Metathesaurus. These subsets do not include MetamorphoSys, the Semantic Network, or the Specialist Lexicon and Lexical Tools. As of the 2023AA release, these subsets do not include obsolete / suppressible content. Obsolete / suppressible content is still available from the Full UMLS Release Files.

Release Description File Size (compressed) File Size (uncompressed) Date
UMLS Metathesaurus Full Subset Download the UMLS Metathesaurus Full Subset if you want to load the complete Metathesaurus data directly into your local environment without any subsetting or additional customization. MYSQL and Oracle load scripts are included. To browse the UMLS Metathesaurus data, visit the UMLS Metathesaurus Browser .

MD5 checksum: 3dcf88cefc73bbde68fef7431603eeba
4.0 GB 27.1 GB November 6, 2023
UMLS Metathesaurus Level 0 Subset
This subset includes only level 0 source vocabularies . Level 0 vocabularies do not have any additional restrictions beyond the standard license terms. MYSQL and Oracle load scripts are included.

MD5 checksum: 585835ff2fee4194e2e2880e3673d0d0 		1.6 GB 9.2 GB November 6, 2023
MRCONSO.RRF The most widely used UMLS file. This file includes names, codes, and concepts from over 200 source vocabularies. More information...

MD5 checksum: 91fe5639d04075a254176cec35064872 		368 MB 1.7 GB November 6, 2023

We are considering a new approach to generating UMLS subsets, and we would like your feedback. The new approach may involve producing new precomputed subsets or configuring subsets in a web browser instead of in MetamorphoSys. We are interested in knowing which features of MetamorphoSys our users consider essential. Please submit your comments to the NLM Help Desk using the subject line: “UMLS Subsets”

2023AB Full UMLS Release Files

Release Description File Size (compressed) File Size (uncompressed) Date
Full Release (umls-2023AB-full.zip) The full release includes the UMLS Metathesaurus, Semantic Network, Specialist Lexicon and Lexical Tools, database load scripts, and MetamorphoSys for customizing your UMLS subset and browsing the data. 5.1 GB 34.2 GB November 6, 2023

Download Notes:

  • Download the UMLS zip file and extract the contents to a single directory.
  • Read the README file after downloading, which includes information on installing the UMLS Knowledge Sources and highlights changes for this release.
  • Each UMLS release includes MetamorphoSys, required to install Knowledge Sources files, and to create, search and browse customized Metathesaurus subsets. MetamorphoSys requires a minimum of 40 GB of free hard disk and takes 2-10 hours to run on a range of platforms tested. The actual time will depend on your configuration, hardware and operating system platforms.

UMLS Metathesaurus History Files

These files include data that has been dropped from the UMLS Metathesaurus starting with the 2004AA release. Please let us know if you find these files useful by submitting your comments to the NLM Help Desk using the subject line: “UMLS History Files”.

Release Description File Size (compressed) File Size (uncompressed) Date
UMLS History Files
  • Concept History (MRCONSO_HISTORY.txt) - This file contains all atoms, concepts, and codes that were dropped from the UMLS Metathesaurus MRCONSO.RRF starting with the 2004AA release. This file resembles the MRCONSO.RRF file , but there is an additional column that indicates the last version of the UMLS in which each atom appeared.
  • Relation History (MRREL_HISTORY.txt) - This file contains all relations dropped from the UMLS Metathesaurus MRREL.RRF file starting with the 2004AA release. This file resembles the MRREL.RRF , but there is an additional column that indicates the last version of the UMLS in which the relation appeared.
  • Source Vocabulary History (MRSAB_HISTORY.txt) - This file includes a row for every version of every UMLS source vocabulary updated in the UMLS Metathesaurus MRSAB.RRF file starting with the 2004AA release. This file resembles the MRSAB.RRF file, but there is an additional column that indicates the version in which the UMLS source vocabulary was updated.

MD5 checksum: d6a10ceff023431b05b6fc3a999304a5

1.1 GB 7.7 GB November 6, 2023

UMLS Release Archives 2002-2023AA

Last Reviewed: November 6, 2023