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SNOMED CT United States Edition

The SNOMED CT United States (US) Edition is the official source of SNOMED CT for use in US healthcare systems. The US Edition is a standalone release that combines the content of both the US Extension and the International releases of SNOMED CT. NLM distributes the US Edition of SNOMED CT to licensed individuals via the UMLS Terminology Services. Please see the Licensing page to learn more about licensing and how to register to obtain an Affiliate License.

For additional information regarding ONC Regulations please see this ONC FAQ.

For older versions of the US Edition of SNOMED CT, please see the SNOMED CT Archives page.

Current US Edition Release

NOTE: For the latest SNOMED CT SARS-CoV-2/COVID-19 content, see:

March 2022

Version: 20220301

Release Date: March 1, 2022

The March 2022 SNOMED CT United States (US) Edition release is now available for download. In addition to the 279 new active concepts specific to the US Extension, the March 2022 SNOMED CT US Edition also includes the SNOMED CT COVID-19 Related Content published in the January 2022 SNOMED CT International Edition. This latest version of the US Edition also includes the SNOMED CT to ICD-10-CM reference set, with over 126,000 SNOMED CT source concepts mapped to ICD-10-CM targets.

Please note - While the SNOMED CT International Edition is moving to monthly releases, the US Edition of SNOMED CT will remain on the current bi-annual release schedule of March and September.

Download Now!

MD5 hash: 44efd123f83d4a8a76d4da0d9239888b

Download | View Release Notes

Download Transitive Closure Resources

MD5 hash: 38464e63cb1c058282fc081d66080dbc

Download SNOMED CT to ICD-10-CM Mapping Resources

MD5 hash: f37d211a9c4f6349de47b179ef09c0f0

View Release Notes

View Technical Specifications

Announcement -

  1. Changes in the March 2022 US Edition release

    SNOMED International are transitioning to a monthly delivery schedule for the International Edition of SNOMED CT. This transition will necessarily involve a few changes to process/packages:

    • Delta files have been removed from both International and Managed Service release packages, including the US Edition. A Delta Generation service will be provided for those who need it. The Delta Generation Tool allows users to create their own Delta between two fixed release dates - you can find it here:
    • There is no longer any need to separate the Map files from the International Edition - the ICD-0/ICD-10 Maps will continue to be published in each Monthly International Edition release package (in line with that month's content) for the foreseeable future, unless we experience issues with the new process in Production, and they need to be removed at a later date.

    The first monthly Release of the SNOMED CT International Edition is currently planned for the 28th February 2022, however the Delta files have been removed from the International Edition from the January 2022 Release, and from the US Edition from the March 2022 Release onwards.

  2. Significant changes in the September 2021 US Edition release

    Concrete Domains launch

    Following on from the successful technical previews of the impending Concrete Domains changes, released in September 2020 and February 2021 respectively, SNOMED International implemented these changes in the July 2021 International Edition Production release. This constituted drug concept strengths and counts expressed as concrete values in a new Relationships file.

    These files have therefore been propagated through into the September 2021 US Edition release package.

    • Inferred Relationship file changes:
      • All relationships for values of strength and count for medical products inactivated
      • All relationships for attributes of strength and count for medicinal products inactivated
      • New relationships for new concept model data attributes of strength, count, product name, and supplier for medicinal products will be added
    • Stated OWL Axiom file changes:
      • Existing drug concept axioms updated to use concrete values
      • Existing strength and count attribute types will be inactivated, replaced with new ones using the same FSNs.
    • New Inferred "Relationship Concrete Values" files:
      • New concrete values relationship files added to the RF2 package structure, containing all new relationships for values of strength and count for medical products:
        • sct2_RelationshipConcreteValues_Delta_US1000124_20210901.txt
        • sct2_RelationshipConcreteValues_Full_US1000124_20210901.txt
        • sct2_RelationshipConcreteValues_Snapshot_US1000124_20210901.txt
    • MRCM file changes:
      • MRCM includes new rows to indicate that the new attribute types are expected to take a concrete domain - specifically numbers - as target values.

Last Reviewed: April 7, 2020