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How to License and Access the Unified Medical Language System® (UMLS®) Data

UMLS licenses are issued only to individuals and not to groups or organizations. You must accept the terms of the UMLS Metathesaurus License (PDF) and create a UMLS Terminology Services (UTS) account for access to the UMLS, terminology browsers, and related resources such as RxNorm and SNOMED CT®.

Each UMLS Release contains the three Knowledge Sources: the Metathesaurus, the Semantic Network, and the SPECIALIST Lexicon. A complete description of the Knowledge Sources and their distribution formats can be found on the UMLS Web site.

There is no charge for licensing any part of the UMLS from NLM. There may be separate license fees associated with usage of SNOMED CT which is owned by the International Health Terminology Standards Development Organization (IHTSDO). The SNOMED CT® Affiliate Licence Agreement is included as Appendix 2 of the UMLS Metathesaurus License and outlines possible costs. NLM is a member of IHTSDO and there is no charge for SNOMED CT use in the United States and other member countries.  For information about fees in non-member countries, see the IHTSDO web site:

Users should carefully read the license agreement before re-distributing any content in any type of application as there may be additional restrictions, permissions or copyright considerations imposed by the content providers. Users must contact the vocabulary content providers regarding any use that is not covered by the license. The content providers may charge fees for these additional uses of their content. Appendix 1 lists contact information for each content provider.

How to Request a License and Create a UTS account
How to Access UMLS Data
Reporting Requirements
Data Use Restrictions
Application Programming Interface (API) Options
Contact Information

How to Request a License and Create a UTS Account:

  1. Click "Sign Up" on the UTS homepage.
  2. Read and accept the Web-based UMLS Metathesaurus License and its appendices: UMLS Metathesaurus® Source Vocabularies (Appendix 1) and SNOMED CT® Affiliate Licence Agreement (Appendix 2).
  3. Complete and submit the license request form, including your self-assigned UTS account username and password.
  4. Receive first e-mail from NLM and authenticate your license request using the link provided in the e-mail.
  5. Receive another e-mail from NLM after your license request has been reviewed and approved. You may now sign in to the UTS.
    • This e-mail is your license approval. NLM will send the license approval e-mail within 5 business days after reviewing your authenticated license request.

Questions relating to the licensing process should be sent to

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How to Access UMLS Data:

Sign in to the UTS to access applications, downloads, resources, and to request a DVD.

UTS Applications

The UTS Applications menu provides access to browsers for the Metathesaurus, Semantic Network, and SNOMED CT.


The Downloads menu provides access to:

  • UMLS Knowledge Sources
  • RxNorm Files
  • SNOMED CT Files


The Resources menu provides access to NLM-created and other resources such as:

  • Semantic Knowledge Representation
  • SPECIALIST Lexicon*
  • UMLS Community* (user-submitted contributions)
  • IHTSDO Website for SNOMED CT users

*A license is not required to access these resources.


UMLS data are available on DVD at no charge. The DVD is mailed upon request or shortly after a new UMLS Release is made available. To request or cancel a DVD:

  • Click "My Profile" then "Edit Profile."
  • Check or uncheck the box "I would like to receive a DVD containing the UMLS data."
  • Click "Save Profile" to finish.

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Reporting Requirements

UMLS Metathesaurus Annual Report
The UMLS Metathesaurus License requires you to complete an Annual Report, per Section 5 of the UMLS Metathesaurus License. If the Annual Report is not completed by the deadline, you forfeit access to the UTS and your license will be terminated.

IHTSDO Affiliate License Statement of Account
The SNOMED CT® Affiliate Licence Agreement requires separate semi-annual reporting. The SNOMED CT® Affiliate Licence Agreement is included as Appendix 2 of the UMLS Metathesaurus License.

NLM will send e-mails with instructions on how to fulfill these reporting requirements.

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Data Use Restrictions

Section 12 of the UMLS Metathesaurus License outlines additional restrictions on source vocabulary use. These restrictions apply to the vocabularies listed in Appendix 1 of the license.

SNOMED CT usage restrictions are outlined in Appendix 2 of the license agreement .

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Application Programming Interface (API) Options

UTS users may remotely query the UMLS Terminology Browser using the Web services API. More information is available under Technical in the Documentation menu on the UTS.

The UTS includes a RESTful interface that allows developers to verify that their users have an active license. Application developers must be authorized distributors of UMLS data to use this service. More information is available under Technical in the Documentation menu on the UTS.

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Contact Information

Questions about obtaining a UMLS Metathesaurus License? E-mail

Other UMLS related questions? See the UMLS Customer Support Web page.

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