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Unified Medical Language System® (UMLS®)

2014AA UMLS® Release Notes and Bugs

What's New


The 2014AA Metathesaurus contains more than 2.9 million concepts and 11.6 million unique concept names from over 150 source vocabularies.

One new source added: 

  • Veterinary Extension to SNOMED CT (SNOMEDCT_VET)

25 English sources and 19 translation sources were updated.  These include MeSH®, MedDRA, RxNorm, and SNOMED CT® (English and Spanish).  A complete list is available in the Updated Sources section of the Release Documentation.  For more 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.

Data Changes

  • The Metathesaurus no longer includes the Metathesaurus CPT Hierarchical Terms source (SAB=MTHCH).  The full CPT hierarchy is available within SAB=CPT as of 2014AA.

Logical Observation Identifier Names and Codes (LOINC)

  • The content of the 18 LOINC subsources (such as patient assessment instruments) is now attributed to SAB=LNC, with SRL=0.  As a result there are 18 fewer SABs in the Metathesaurus.  Users of this content are expected to abide by the terms of the UMLS Metathesaurus License agreement as outlined in Appendix 1.  The 18 SABs that no longer appear in the Metathesaurus are:
    • LNC244_ASQ_3
    • LNC244_BRADEN
    • LNC244_CAM
    • LNC244_FACIT
    • LNC244_FLACC
    • LNC244_MDS20
    • LNC244_MLHFQ
    • LNC244_NPUAP
    • LNC244_OASIS
    • LNC244_OPTIMAL
    • LNC244_PHQ_9
    • LNC244_RHO
    • LNC244_SPERTUS
    • LNC244_VR_12
    • LNC244_WHO
    • LNC242_AD8
    • LNC242_MDS30


  • A full Metathesaurus subset now requires 22.8 GB of disk space.
  • The active release requires 22.1 GB of disk space.

SPECIALIST Lexicon and Lexical Tools

  • The SPECIALIST Lexicon  has been updated (2014 Release).
  • The Lexical Tools have been updated (2014 Release) and integrate data from the SPECIALIST Lexicon, 2014 Release. The Lexical Tools include the Full and Lite versions of lvg.2014.
  • The Metathesaurus index files were processed using the updated lvg files.

UMLS Learning Resources
2014AA Source Release Documentation Web pages will be published following the release.

Users who are new to the UMLS are encouraged to review the New Users' homepage. This page includes the new UMLS Quick Start Guide, online demonstrations, step-by-step guides, and a link to UMLS training materials.


There are no known problems for the 2014AA release. Please send any issues or concerns to NLM Customer Service.

UMLS Problems (Bugs) for Previous Versions

Release information for the RRF Browser