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© 2024 International Health Terminology Standards Development Organisation.  All rights reserved.  SNOMED CT® was originally created by the College of American Pathologists.

This document forms part of the International Edition release of SNOMED CT® distributed by International Health Terminology Standards Development Organisation, trading as SNOMED International, and is subject to the SNOMED CT® Affiliate License, details of which may be found at

No part of this document may be reproduced or transmitted in any form or by any means, or stored in any kind of retrieval system, except by an Affiliate of SNOMED International in accordance with the SNOMED CT® Affiliate License. Any modification of this document (including without limitation the removal or modification of this notice) is prohibited without the express written permission of SNOMED International.

Any copy of this document that is not obtained directly from SNOMED International [or a Member of SNOMED International] is not controlled by SNOMED International, and may have been modified and may be out of date. Any recipient of this document who has received it by other means is encouraged to obtain a copy directly from SNOMED International [or a Member of SNOMED International. Details of the Members of SNOMED International may be found at].

Page At A Glance

Table Of Contents



SNOMED CT terminology provides a common language that enables a consistent way of indexing, storing, retrieving, and aggregating clinical data across specialties and sites of care.

SNOMED International maintains the SNOMED CT technical design, the content architecture, the SNOMED CT content (includes the concepts table, the descriptions table, the relationships table, a history table, and ICD mappings), and related technical documentation.


This document provides a summarized description of the content changes included in the March 2020 INTERIM release of SNOMED Clinical Terms® (SCT) International Release.

It also includes technical notes detailing the known issues which have been identified and agreed to be released. These are content or technical issues where the root cause is understood, and the fix has been discussed and agreed, but has yet to be implemented.

The SNOMED International Release Notes are available alongside the INTERIM March 2020 International Edition release.


This document is written for the purpose described above and is not intended to provide details of the technical specifications for SNOMED CT or encompass every change made during the release.


The audience includes National Release Centers, WHO-FIC release centers, vendors of electronic health records, terminology developers and managers who wish to have an understanding of changes that have been incorporated into the INTERIM March 2020 International Edition release.

Content Development Activity


This INTERIM International Edition Release has been created as part of the ongoing global effort to tackle the Coronavirus outbreak, and as such includes the updated Coronavirus descriptions for Members and implementers. This is a full International Edition Release package containing changes to the content detailed in the news item ( under the following conditions:

- following SNOMED International's critical incident policy, there will NOT be a recall of the January release, simply an update in response to international renaming, to ensure that SNOMED CT is current when assisting with the global Coronavirus effort
- implementers are encouraged to update to the new edition, however, they are NOT obliged to do so as the concept modelling and identifiers are not being modified
- the entirety of these changes will also be incorporated into the upcoming July 2020 International Edition Release

New content added for 2019 novel coronavirus

A set of new components have been added and refined for the March 2020 release:

RF2 fileNumber of ChangesChanges for this release
Description files37

24 records added, with all 7 Coronavirus concepts having 3x records added each (1x FSN = 2x Synonyms) plus Core concept description added back in referencing March 2020:

8405340013950925017COVID-19 vaccination 
8405440043950926016Suspected COVID-19 
8405350003947177019Antibody to severe acute respiratory syndrome coronavirus 2 (substance) 
8405350003947178012Antibody to severe acute respiratory syndrome coronavirus 2 
8405350003947179016Antibody to SARS-CoV-2 
8405360043947180018Antigen of severe acute respiratory syndrome coronavirus 2 (substance) 
8405360043947181019Antigen of severe acute respiratory syndrome coronavirus 2 
8405360043947182014Antigen of SARS-CoV-2 
8405390063947183016Disease caused by severe acute respiratory syndrome coronavirus 2 (disorder) 
8405390063947184010Disease caused by severe acute respiratory syndrome coronavirus 2 
8405460023947186012Exposure to severe acute respiratory syndrome coronavirus 2 (event) 
8405460023947187015Exposure to SARS-CoV-2 
8405460023947188013Exposure to severe acute respiratory syndrome coronavirus 2 
8405330073947189017Severe acute respiratory syndrome coronavirus 2 (organism) 
8405330073947191013Severe acute respiratory syndrome coronavirus 2 
8405340013947192018Severe acute respiratory syndrome coronavirus 2 vaccination (procedure) 
8405340013947193011SARS-CoV-2 vaccination 
8405340013947194017Severe acute respiratory syndrome coronavirus 2 vaccination 
8405440043947195016Suspected disease caused by SARS-CoV-2 
8405440043947196015Suspected disease caused by severe acute respiratory coronavirus 2 
8405440043947197012Suspected disease caused by severe acute respiratory coronavirus 2 (situation) 
1388750053947198019SNOMED Clinical Terms version: 20200309 [R] (March 2020 Interim Release) 

Plus 15 records inactivated, with all 7 Coronavirus concepts having 1 description inactivated each, plus the 1 Core concept description record inactivated as still referencing January 2020.

Language refset files88

16 records updated, with all 16 language refset records from January 2020 being changed from Preferred to Acceptable as part of these changes.

Plus 30 records inactivated, due to the inactivation of both language refset records for all 7 original concepts created in January 2020, plus the inactivation of the original January 2020 Core description.

Plus 48 records added, with both Language records (EN-GB + EN-US) for each of the 24 new Descriptions above.

Attribute Value files15

15 records added, due to the inactivations of the descriptions (above).

ExtendedMap files3

3 records added, due to the ICD-10 map records added for the new Coronavirus content.

ModuleDependency files


3 records updated, as expected for March 2020 effectiveTimes

Readme file

March 2020 dates updated + Coronavirus explanations added, as expected

Concept files0

No changes required

Relationship files0No changes required

OwlExpression files0No changes required

Stated Relationship files0No changes required

TextDefinition files0No changes required

SimpleMap files0No changes required

Simple Refset files0No changes required

MRCM AttributeDomain files0No changes required

MRCM AttributeRange files0

No changes required

MRCM Domain files0

No changes required

Association Reference files0

No changes required

SNOMED CT derived products

ICD-10 map

The SNOMED CT to the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (© World Health organisation 1994) 2016 Version map (SNOMED CT to ICD-10 Map) is included in the SNOMED CT International release as a Baseline. The SNOMED CT to ICD-10 Map was created to support the epidemiological, statistical and administrative reporting needs of SNOMED International member countries and WHO Collaborating Centres.

The SNOMED CT to ICD-10 Map is released in Release Format 2 (RF2) only. It is located in the file der2_iisssccRefset_ExtendedMapFull_INT_20200309.txt, which is in the Map folder under Refset, in each of the three RF2 Release Type folders. 

The SNOMED CT to ICD-10 Map is released as Refset 447562003 |ICD-10 complex map reference set (foundation metadata concept)|.

Content development activity summary

The map is a directed set of relationships from SNOMED CT source concepts to ICD-10 target classification codes.  The SNOMED CT source domains for the MAP are limited to subtypes of 404684003 |clinical finding|, 272379006 |event| and 243796009 |situation with explicit context|.  The target classification codes are ICD-10 2016 release. 

Mapped content for March 2020

The map provided for the March 2020 release has been updated in line with the Coronavirus changes for both the January 2020 and March 2020 International Edition releases:

840546002ALWAYS Z20.8 Z20.8447561005447637006

We would welcome feedback on any issues that users of the map may detect when using the map. Issues should be submitted via

Technical Guide Exemplars

The Technical Guide Exemplars document has now been moved from the International Edition release package to a Confluence page.  This page can be found as part of the ICD-10 Mapping Technical Guide (see Appendix B), which is hosted here:


No changes to the ICD-0 map were required for this Interim release.

SNOMED CT to OWL conversion and classification

The repository containing the toolkit enabling simple SNOMED CT to OWL conversion and classification can be found here, including documentation on its use:

Please contact SNOMED International at if you would like to provide any feedback on ways to extend and improve the new toolkit.

Technical notes

Known Issues

Known Issues are content or technical issues where the root cause is understood, and the resolution has been discussed and agreed but has yet to be implemented.  This can be due to a number of reasons, from lack of capacity within the current editing cycle, to the risk of impact to the stability of SNOMED CT if the fix were to be deployed at that stage in the Product lifecycle.  

For the SNOMED CT March 2020 International edition, the following Known Issues were identified, and agreed to be resolved in future editing cycles:

Key Summary Description


Resolved Issues

Resolved issues are Known Issues which were not fixed as part of the previous release lifecycle, but which have now been resolved in the latest release.  They can also be issues found during the Alpha and Beta testing of the current release, which were resolved before the final deployment of the associated Member release.  Finally they can be issues which were reported or found during the testing phase, but which have been closed without any action taken.  

The Resolved Issues for the Snomed CT March 2020 International edition can be found here:

Key Summary Description Resolved

Technical updates

RF2 package format

For future reference, the RF2 package convention dictates that it contains all relevant files, regardless of whether or not there is content to be included in each particular release.  Therefore, the package contains a mixture of files which contain both header rows and content data, and also files that are intentionally left blank (including only a header record).  The reason that these files are not removed from the package is to draw a clear distinction between files that:

  • have been deprecated (and therefore removed from the package completely), due to the content no longer being relevant to RF2 in this or future releases, and 
  • happen to contain no data in this particular release (and are therefore included in the package but left blank, with only a header record), but are still relevant to RF2, and could therefore potentially contain data in future releases.

This allows users to easily distinguish between files that have purposefully been removed or not, as otherwise if files in option 2 above were left out of the package it could be interpreted as an error, rather than an intentional lack of content in that release.

RF2 file consumption

The changes are delivered in the usual Delta, Full + Snapshot files, with the Delta relative to the January 2020 International Edition release.

The current plan is to also include the same changes in the July 2020 International Edition, for those users who do not consume this March 2020 Interim release package.  

For those who do use this March 2020 content, you should then avoid using the Delta files from the July 2020 International Edition, which will necessarily include duplicate records for these few changes.  The July 2020 Full and Snapshot files will work without issue for all users, regardless of whether or not they utilised this March 2020 release package.

Early visibility of impending change in the July 2020 International edition

Please see the following page for details of all upcoming changes planned for July 2020 and beyond:  July 2020 Early Visibility Release Notice - Planned changes to upcoming SNOMED International Release packages

All links provide information that is correct and current at the time of this Release.  Updated versions may be available at a later date, but if so these will need to be requested from the relevant SNOMED International teams.

NOTE:  To access any of the links in the pdf document, please visit the Release Notes @


Final Version






Monica HarryApproved


Maria BraithwaiteApproved


Rory DavidsonApproved

Draft Amendment History







Andrew Atkinson

First draft for review and comment



Maria Braithwaite / Andrew AtkinsonFinal updates, including map record count update


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