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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

September 2019

Version: 20190901

Release Date: September 1, 2019


The September 2019 SNOMED CT United States (US) Edition release is now available for download. This release includes an updated SNOMED CT to ICD-10-CM mapping reference with over 123,000 SNOMED CT source concepts mapped to ICD-10-CM targets. Please note that no new US-specific concepts were added in this release.


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MD5 hash: 5bb4db2a14ae1dd022722f775b6de9df

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Download SNOMED CT to ICD-10-CM Mapping Resources

MD5 hash: 13d5a948881e9ba5992ca7482d7a801d

View Release Notes

View Technical Specifications


Announcement - File Changes Expected in the March 2020 US Edition

To continue to align with the SNOMED CT International Edition, the following changes will be implemented starting with the March 2020 US Edition. These changes will allow for the continued efforts towards having a zip file including only data with additional supplemental documentation and artifacts available separately.

  • Deprecation of the Resources folder
    • This aligns with the SNOMED CT International Edition release package which no longer includes a Resources folder.
  • Removal of Transitive Closure resources from the US Edition release zip file
    • The Transitive Closure resources will be made available alongside the US Edition of SNOMED CT as a bundled zip download. The following resources will be updated and bundled together and made available with each new US Edition release:
      • res2_TransitiveClosure_US1000124_YYYYMMDD.txt
      • tls2_TransitiveClosure_US1000124_YYYYMMDD.pl

Any questions or comments regarding these upcoming changes can be sent to NLM Customer Support https://support.nlm.nih.gov/.

Please Note - Important changes in the September 2019 US Edition

  1. File Changes in the September 2019 US Edition


    As reported in March 2019, to continue to align with the SNOMED CT International Edition, the the following changes have been implemented in this September 2019 US Edition. These changes will allow for the continued efforts towards having a zip file including only data with additional supplemental documentation and artifacts available separately.

    • Deprecation of the Documentation folder
    • Deprecation of the doc_Icd10MapTechnicalGuideExemplars_[date].xlsx file
    • Removal of SNOMED CT to ICD-10-CM documentation and resources from the US Edition download and made available alongside the US Edition of SNOMED CT as a bundled download - SNOMED CT to ICD-10-CM Mapping Resources.


    Please see section "3.3.1 File Changes in the September 2019 US Edition" in the September 2019 SNOMED CT US Edition Release Notes for more information.

  2. Combination of two new refsets - OWLAxiom and OWLOntology


    The US Edition is following the International Edition with the changes to the Stated Relationships and two new OWL refsets.

    Please see section "3.3.2 Combination of two new refsets - OWLAxiom and OWLOntology" in the September 2019 SNOMED CT US Edition Release Notes for more information.

  3. Replacement of the Stated Relationship files with the new OWL Axiom refset files


    The International Edition and US Edition packages will include both inactive Stated Relationships plus a complete OWL file (combined) from July 2019 (International content) and September 2019 (US Extension content) effectiveTime onwards (ie) with NO history of OWL records that weren’t included in the January 2019 International Edition and March 2019 US Edition package (as opposed to the optional package).

    Please see section "3.3.3 Replacement of the Stated Relationship files with the new OWL Axiom refset files" in the September 2019 SNOMED CT US Edition Release Notes for more information.

  4. RF2 package format


    Similar to the International Edition, the US Edition will follow the technical specifications for RF2 packaging format.

    Please see section "3.3.4 RF2 package format" in the September 2019 SNOMED CT US Edition Release Notes for more information.

Last Reviewed: September 4, 2018