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Unified Medical Language System® (UMLS®)

2012AA UMLS® Release Notes and Bugs

What's New


The 2012AA Metathesaurus contains more than 2.7 million concepts and 10.8 million unique concept names from over 160 source vocabularies.

Three new source was added:

  • US Extension to SNOMED CT (SCTUSX)
  • Quality of Life Outcomes in Neurological Disorders (LNC_NEUROQOL)
  • Outpatient Physical Therapy Improvement in Movement Assessment Log (LNC_OPTIMAL)

One new translation was added:

  • Norwegian translation of the Medical Subject Headings (MSHNOR)

38 English sources and 20 translation sources were updated. These include MedlinePlus®, 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 maximum length for the attribute name (ATN) field in the MRSAT file is now 100 characters. The database load scripts produced by MetamorphoSys reflect this change.
  • Two source name changes appear in MRSAB. Their Metathesaurus source abbreviations (SAB) remain the same.
    • National Drug Data File Plus Vocabulary (SAB=NDDF) is now FDB MedKnowledge (formerly NDDF Plus).
    • Gold Standard Alchemy (SAB=GS) is now Gold Standard Drug Database.

Clinical Care Classification

  • Clinical Care Classification (CCC) is the update of the former Home Health Classification (HHC). The 2003 version of HHC remains as one of the 2012AA Metathesaurus vocabulary sources. HHC will be removed out of the Metathesaurus in 2012AB.

US Extension to SNOMED CT

  • The Metathesaurus includes the March 1 version of the US Extension to SNOMED CT.


  • A full Metathesaurus subset now requires 23 GB of disk space.

SPECIALIST Lexicon and Lexical Tools

  • The SPECIALIST Lexicon has been updated (2012 Release).
  • The Lexical Tools have been updated (2012 Release) and integrate data from the SPECIALIST Lexicon, 2012 Release. The Lexical Tools include the Full and Lite versions of lvg.2012.
  • The Metathesaurus index files were processed using the updated lvg files.

UMLS Learning Resources

2012AA 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.


Title: MRSAB includes incorrect version date for LNC_NEUROQOL
Problem: The MRSAB file lists LNC_NEUROQOL with a 2001 version date for its VSAB.
Solution: The correct version date is 2010. This error will be corrected in the 2012AB Release.
Date Posted: May 7, 2012

Title: US Extension to SNOMED CT Error
Problem: Several rows misspell “education”.
Solution: This error will be corrected in the October version of the US Extension and the 2012AB UMLS Release.
Date Posted: May 7, 2012

Title: CPT Spanish Atoms Not Released
Problem: Approximately 4,000 CPT Spanish Preferred Term (PT) atoms were erroneously not released in MRCONSO.RRF (MRCON and MRSO for ORF). 
Solution: This error will be corrected in the 2012AB Release.
Date Posted: May 7, 2012

Title: ICD10CM_2012 to ICD9CM_2012 Reimbursement Mapping Errors

  • MAPSETCUI C3264360 in MRMAP and MRSMAP (ICD10CM_2012 to ICD9CM_2012 Reimbursement Mapping) has 669 rows with false positive mappings. The value of the TOEXPR field for these rows is ‘NODX’, which is intended to mean the absence of a map. These rows were erroneously assigned a rel/rela combination of RQ/mapped_to in MRMAP, whereas they should have the rel ‘XR’, which means ‘map to nothing’.
  • MAPSETCUI C3264360 has 85 TOEXPR values that have an erroneous trailing decimal period. Example: C3264360|ICD10CM|||AT146354901||M21.41||M21.41|SDUI|||RQ|mapped_to|15206||734.|SDUI|||||||||

Solution: These errors will be corrected in the 2012AB Release.
Date Posted: May 7, 2012

UMLS Problems (Bugs) for Previous Versions

Release information for the RRF Browser