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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: http://snomed.org/covid-19

September 2021

Version: 20210901

Release Date: September 1, 2021


The September 2021 SNOMED CT United States (US) Edition release is now available for download. In addition to the 501 new active concepts specific to the US Extension, the September 2021 SNOMED CT US Edition also includes the SNOMED CT COVID-19 Related Content published in the July 2021 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.


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MD5 hash: c18fdde890c51df2c32439c7647b60d4

Download | View Release Notes

MD5 hash: 45a2841a58b577539c6d75579f63a1d7

Download Transitive Closure Resources

MD5 hash: 8227862663fa412f7d26565848068bf2

Download SNOMED CT to ICD-10-CM Mapping Resources

MD5 hash: affecb0929c916bb9e86a460f559883d

View Release Notes

View Technical Specifications


Announcement - 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