Skip Navigation Bar
NLM Technical Bulletin Header
Article Navigation Bar Table of Contents NLM Technical Bulletin Home Page Back Issues
 April 30, 2004 [posted]
 Unified Medical Language System® (UMLS®) Changes

drop cap letter for u MLS Web Site and Documentation
The UMLS Web site has been restructured to enhance access to existing information and to add new information to improve the understanding of and access to the UMLS resources. Additional materials will be added in the coming weeks. See:

New UMLS Release
NLM plans to release the 2004AA quarterly edition of the UMLS Knowledge Sources soon. This will be the first release containing SNOMED Clinical Terms (SNOMED CT®).

New License Required
NLM® will distribute SNOMED CT within the UMLS Metathesaurus under the terms of a revised UMLS license agreement that includes additional language concerning SNOMED CT. U.S. licensees will be able to use SNOMED (as distributed by NLM) in the U.S. without charge and without signing a separate license agreement with the College of American Pathologists (CAP), SNOMED's producer. Non-U.S. UMLS licensees will continue to require a separate license agreement with the CAP for production uses of SNOMED CT. Current UMLS users will have to sign the revised license agreement before receiving the next 2004AA edition of the UMLS, which will include SNOMED CT.

License Registration and Renewals Now Online
The new electronic UMLS license process is now available at: This new process is completely electronic; no licensee digital or electronic signatures are required. After an NLM official electronically signs, an e-mail message will then be sent back by NLM with the UMLS license number. Keep a printed copy of this for your records—no paper license copy will be sent.

Knowledge Source Server Access
Existing server users may update their server accounts with their new license numbers. Instructions have been sent to current UMLS licensees about how to do this. UMLS licensees will have to wait at least 10 minutes from receipt of their new licenses before accessing the server, because the server is updated with new license information every five minutes, and a few extra minutes are being allowed for other operations. After a brief grace period, old license numbers and any accounts created under them will no longer work on the server. During the grace period, old license numbers will enable downloading of only UMLS versions earlier than 2004AA. To access or download 2004AA data, new license numbers will be required. The server can be accessed at:

Download of the 2004AA UMLS Edition
The distribution will be made available for downloading from the UMLS Knowledge Source Server as usual. However, the size of the release is expected to be quite large—approximately 1.9 GB compressed. Depending on the licensee's Internet connection (T3 or T1 large pipe, etc.) it may take from an hour or two to many hours to download the compressed files; a T1 line with 1 mps throughput will require over five hours.

A DVD-ROM (one disk, with MetamorphoSys as both the UMLS installation and Metathesaurus subsetting program for PC, UNIX and Mac machines) will be available by request from: Licensees who request a DVD should include their new license number. Because of the large size of the files, NLM has switched from multiple CD-ROM disks to one DVD-ROM disk. DVD drives are becoming more prevalent on personal computers. External DVD drives may now be purchased for less than $75.00. It is expected that the DVD containing the 2004AA release will be mailed to all licensed requesters soon.

API and Interactive Access via the UMLS Knowledge Source Server
Licensees will be able to interface their programmed applications via the server API and also to conduct searches using the server search engine (via their Web browser). Access via these mechanisms for the 2004AA edition is expected soon.

As indicated above, MetamorphoSys has been expanded to serve as the install program for all three UMLS Knowledge Sources (Metathesaurus, Semantic Network, SPECIALIST Lexicon and lexical programs). All users who load UMLS data in a local system must use MetamorphoSys. Users may choose between 7-bit ASCII and the UTF-8 Unicode characters and old or new release formats. Customization features have been expanded in MetamorphoSys.

If you experience problems with the new licensing process or have any questions concerning UMLS changes, contact NLM Customer Service:
By e-mail:
By phone:    1-888-FINDNLM (1-888-346-3656)

By Carolyn B. Tilley
Bibliographic Services Division

black line separting article from citation

Tilley CB. Unified Medical Language System® (UMLS®) Changes. NLM Tech Bull. 2004 Mar-Apr;(337):e9.


Article Navigation Bar NLM Technical Bulletin Home Page Back Issues Index Previous Page Next Article
U.S. National Library of Medicine, 8600 Rockville Pike, Bethesda, MD 20894
National Institutes of Health, Department of Health & Human Services
Copyright, Privacy, Accessibility, Freedom of Information Act (FOIA)
HHS Vulnerability Disclosure
Last updated: 12 April 2012