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
Release Date: March 1, 2023
The March 2023 SNOMED CT United States (US) Edition release is now available for download. This release contains 398 new active concepts specific to the US Extension. The March 2023 US Edition of SNOMED CT is based on the content published in the December 2022 SNOMED CT International Edition and includes any SNOMED CT COVID-19 Related Content published in the December 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 - Due to the move to monthly SNOMED CT International Edition releases, NLM will base the March US Edition of SNOMED CT on the December SNOMED CT International Edition and the September US Edition of SNOMED CT on the June SNOMED CT International Edition. Any changes to this plan will be announced via the NLM SNOMEDCT Announces listserv.
Please note - While the SNOMED CT International Edition has moved to monthly releases, the US Edition of SNOMED CT will remain on the current bi-annual release schedule of March and September.
MD5 hash: 6edcaa1e8851a2a0fb82dc3c88a2950c
Download Transitive Closure Resources
MD5 hash: a3608a23e8fab5e14aefec9fba94ec02
Download SNOMED CT to ICD-10-CM Mapping Resources
MD5 hash: b1e19b1a7c057ea498bdd2930ac1c4e0
View Release Notes
View Technical Specifications
Announcement - Changes in the March 2023 US Edition release
Notice of changes to the US Edition Release package and Transitive Closure Resources package naming convention
As of the March 2023 Release of the US Edition onwards, the RF2 package and the Transitive Closure Resources package naming convention will be changing from:
...to the following:
For the March 2023 US Edition Release, for example, the RF2 package and the Transitive Closure Resources package will be called:
Note: The change to the naming convention only effects the zip package name and the top two folders in the unzipped package. No other folder or file name contained in the release package will be impacted.
Notice of changes to the US Edition Module Dependency Refset Specifications
There has been discussion on the Module Dependency Refset Specifications (MDRS) records regarding dependencies not being transitive, meaning that they cannot be inferred from a chain of dependencies. For example, if module-A depends on module-B and module-B depends on module-C, the dependency of module-A on module-C must still be stated explicitly. This has not been resolved by SNOMED International, as their recent deliberations regarding the possibility of changing the specifications to make MDRS records transitive have concluded that so far, the business case for doing so is not strong enough. Therefore, the US Edition of SNOMED CT still, in theory, has missing MDRS records which should explicitly call out the dependency of the ICD-10CM map module on both Core International modules. As the new automated MDRS functionality also generates these records, it was decided to allow their introduction until SNOMED International decides to change the RF2 specifications. These records have been included in the September 2022 US Edition release by allowing the automated MDRS generation code to add 2 new records to the US Edition MDRS, explicitly calling out the dependency of the ICD-10CM map module on both Core International modules:
- > e37cecd9-329a-4bf2-96eb-befefd9c45c3 20220901 1 5991000124107 900000000000534007 900000000000207008 20220901 20220630
- > 5b163b38-a5e6-4430-aaaa-82663c4bca4a 20220901 1 5991000124107 900000000000534007 900000000000012004 20220901 20220630
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Health IT and Standards Resources
Last Reviewed: April 7, 2020