Skip Navigation Bar

Unified Medical Language System® (UMLS®)

2015AB UMLS® Release Notes and Bugs

What's New


The 2015AB Metathesaurus contains more than 3.2 million concepts and 12.8 million unique concept names from over 190 source vocabularies.

1 new NCI subsource added:

  • NCI_CareLex (Content Archive Resource Exchange Lexicon)

2 new sources added:

  • HPO (Human Phenotype Ontology)
  • MVX (Manufacturers of Vaccines)

19 new LOINC (LNC) translation sources added:

  • LNC-DE-CH (German, Switzerland Edition)       
  • LNC-DE-DE (German, Germany Edition)           
  • LNC-EL-GR (Greek, Greece Edition)      
  • LNC-ES-AR (Spanish, Argentina Edition)
  • LNC-ES-CH (Spanish, Switzerland Edition)         
  • LNC-ES-ES (Spanish, Spain Edition)        
  • LNC-ET-EE (Estonian, Estonia Edition)   
  • LNC-FR-BE (French, Belgium Edition)    
  • LNC-FR-CA (French, Canada Edition)     
  • LNC-FR-CH (French, Switzerland Edition)          
  • LNC-FR-FR (French, France Edition)      
  • LNC-IT-CH (Italian, Switzerland Edition)
  • LNC-IT-IT (Italian, Italy Edition) 
  • LNC-KO-KR (Korean, Korea Edition)      
  • LNC-NL-NL (Dutch, Netherlands Edition)           
  • LNC-PT-BR (Portuguese, Brazil Edition)
  • LNC-RU-RU (Russian, Russia Edition)    
  • LNC-TR-TR (Turkish, Turkey Edition)     
  • LNC-ZH-CN (Chinese, China Edition)     

50 English sources and 11 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.


  • As of 2015AB, MTHFDA no longer appears in the Metathesaurus.


  • A full Metathesaurus subset now requires 25 GB of disk space.
  • The active release requires 24 GB of disk space.

UMLS Learning Resources
2015AB 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 2015AB release. Please send any issues or concerns to NLM Customer Service.

UMLS Problems (Bugs) for Previous Versions

Release information for the RRF Browser