Skip Navigation Bar
National Library of Medicine Technical BulletinNational Library of Medicine Technical Bulletin

Table of Contents: 2019 MAY–JUNE No. 428

Previous Next

UMLS 2019AA Release Available

Wilder V. UMLS 2019AA Release Available. NLM Tech Bull. 2019 May-Jun;(428):e1.

2019 May 09 [posted]

The 2019AA release of the Unified Medical Language System (UMLS) Knowledge Sources is available for download as of May 6, 2019.

The 2019AA Metathesaurus contains approximately 3.85 million concepts and 14.6 million unique concept names from 210 source vocabularies.

Three new NCI sub-sources:

  • NCI_CPTAC (Clinical Proteomic Tumor Analysis Consortium Terms)
  • NCI_EDQM-HC (European Directorate for the Quality of Medicines & Healthcare)
  • NCI_INC (International Neonatal Consortium Terms)

NDF-RT update:

  • This is the final release that will include NDF-RT, NDFRT-FDASPL, and NDFRT-FMTSME. Note that MED-RT is the successor.

66 English sources and 40 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.

New Download Files
For the 2019AA release, we have made the UMLS Metathesaurus files available as a stand-alone download. Download the UMLS Metathesaurus files if you want to load the complete Metathesaurus data directly into your local environment without any subsetting or additional customization. 

We have also produced a stand-alone MRCONSO.RRF file for download. This is the most widely used UMLS file. It includes all UMLS concepts as well as names and codes from over 200 source vocabularies.

SPECIALIST Lexicon and Lexical Tools

  • The release includes the updated SPECIALIST Lexicon (2019 Release).
  • The release includes the updated Lexical Tools (2019 Release) which integrate data from the SPECIALIST Lexicon, 2019 Release. The Lexical Tools include the Full and Lite versions of lvg.2019.
  • The Metathesaurus index files were processed using the updated lvg files.
  • The updated SPECIALIST Lexicon and Lexical Tools feature synonym enhancements that include changes to their file structure. See the SPECIALIST Lexicon and Lexical Tools web sites for details about these file changes and other updates.


  • The full release requires 29.9 GB of disk space.

Reported bugs may be viewed on the Release Notes and Bugs web page.

MetamorphoSys can generate custom load scripts for MySQL, Oracle, or Microsoft Access when creating a Metathesaurus subset or installing the Semantic Network. Instructions are available on the UMLS Load Scripts homepage.

Release Information
To access the UMLS Release files, you must have an active UMLS Metathesaurus License and a valid UTS account. You will be prompted for your UTS username and password when downloading the files.

UMLS Learning Resources
2019AA Source Release Documentation web pages are available.

Additional information regarding the UMLS is available on the UMLS homepage. New users are encouraged to take the UMLS Basics Tutorial and to explore the UMLS Quick Start Guide, and other training materials.

UMLS Terminology Services (UTS)
The UTS Metathesaurus Browser and the UTS SOAP API and REST API include the updated release.

In addition, the UTS SNOMED CT Browser now features the March 2019 US Edition of SNOMED CT.

UMLS User Contributions
UMLS users have extended the functionality of the UMLS in a variety of ways by developing APIs, automation scripts, and natural language processing tools. You can find a list of these on the UMLS Community web page.

Want to add your tool? Send a request to the NLM Help Desk with the subject line: "UMLS Community."

Be sure to include a link to your source code so that other UMLS users can adapt your tool. We are especially interested in:

  • Database load scripts
  • Transformation scripts that convert UMLS data into other formats (for example, RDF or JSON)
  • Scripts that automate any aspect of UMLS installation
  • Applications that leverage UMLS in the processing of text


By Victoria Wilder
MEDLARS Management Section

NLM Technical Bulletin National Library of Medicine National Institutes of Health