Unified Medical Language System® (UMLS®)
SNOMED CT to ICD-10-CM Map
Download the Map
| SNOMED CT to ICD-10-CM Map Version | Derived from SNOMED CT version | Derived from ICD-10-CM version | Documentation | Number of SNOMED CT Concepts |
|---|---|---|---|---|
| SNOMEDCT_ICD10CM_map.201206 - Final Release | July 2011 International Release | 2011 | Release Notes (PDF) | 15,613 |
| SNOMEDCT_ICD10CM_map.201202 - Preview Publication | July 2011 International Release | 2011 | Release Notes (PDF) | 7,277 |
Supporting Materials
- I-MAGIC Demo Page – to see the Map in action. The I-MAGIC (Interactive Map-Assisted Generation of ICD Codes) Algorithm utilizes the SNOMED CT to ICD-10-CM Map in a real-time, interactive manner to generate ICD-10-CM codes. This demo simulates a problem list interface in which the user enters problems with SNOMED CT terms, which are then used to derive ICD-10-CM codes using the Map.
- An I-MAGIC Implementation Guide is now available
- Technical Documentation (PDF) for the SNOMED CT to ICD-10-CM Map and accompanying exemplar file (Excel).
- Frequently Asked Questions
- Mapping from SNOMED CT to ICD-10 and ICD-10-CM presented by Dr. Kin Wah Fung at HIMSS (Healthcare Information and Management Systems Society) 2012 Conference
- How SNOMED CT can help in the ICD-10-CM transition presented by Dr. Kin Wah Fung at the ICD-10 Summit of AHIMA (American Health Information Management Association) 2012
Introduction
SNOMED CT (Systematized Nomenclature of Medicine-Clinical Terms) is considered to be the most comprehensive, multilingual clinical healthcare terminology in the world. It is designed for use in clinical documentation in the Electronic Health Record (EHR). The purpose of the SNOMED CT to ICD-10-CM map (herein referred to as “the Map”) is to support semi-automated generation of ICD-10-CM codes from clinical data encoded in SNOMED CT for reimbursement and statistical purposes.
Use cases supported
The Map can be used in the following scenarios:
- Real-time use by the healthcare provider – In this scenario, the Map is embedded in the problem list application of the EHR used by the physician or other healthcare provider. At the end of a clinic encounter, the clinician updates the problem list, which is encoded in SNOMED CT. The Map-enabled problem list application outputs a list of ICD-10-CM codes based on algorithmic evaluation of map rules, which makes use of patient context (e.g. age, gender) and co-morbidities (other problems on the problem list) to identify the most appropriate candidate ICD-10-CM codes, in accordance with ICD-10-CM coding guidelines and conventions. If necessary, the clinician is prompted for additional information to decide between alternative codes, or to refine the output codes. The clinician confirms the suggested ICD-10-CM codes. (See the I-MAGIC algorithm and demo page)
- Retrospective coding by coding professionals – In this scenario, the Map is used within an application to suggest candidate ICD-10-CM codes to coding professionals based on a stored SNOMED CT encoded problem list. The degree of automation can vary. Textual advice can be displayed in cases where automated rule processing is not available.
Mapping methodology
The mapping methodology follows closely that of the SNOMED CT to ICD-10 Crossmap Project, a collaborative project between the IHTSDO and the World Health Organization. Dual independent mapping by trained terminology specialists is employed to assure quality and reduce variability. Identical maps created independently are accepted as final, while discordant maps are reviewed by a third expert. Regular team meetings are held to discuss problematic and ambiguous cases.
Rule-based mapping
Due to the differences in granularity, emphasis and organizing principles between SNOMED CT and ICD-10-CM, it is not always possible to have a one-to-one map between a SNOMED CT concept and an ICD-10-CM code. To address this challenge, this Map follows an approach that is consistent with the approach used by the IHTSDO and WHO in the construction of the SNOMED CT to ICD-10 rule-based map. When there is a need to choose between alternative ICD-10-CM codes, each possible target code is represented as a “map rule” (the essence of “rule-based mapping”). Related map rules are grouped into a “map group”. Map rules within a map group are evaluated in a prescribed order at run-time, based on contextual information and co-morbidities. Each map group will resolve to at most one ICD-10-CM code. In the event that a SNOMED CT concept requires more than one ICD-10-CM code to fully represent its meaning, the map will consist of multiple map groups.
Scope
All current pre-coordinated SNOMED CT concepts within three hierarchies,(Clinical findings, Events, and Situations with Explicit Context) are potentially in scope for mapping to ICD-10-CM. A priority list of clinically important concepts was identified based on the CORE Problem List Subset of SNOMED CT, which includes frequently seen problems, and the Convergent Medical Terminology contents donated by Kaiser Permanente. Only concepts that are in the international release are mapped at this stage. Expansion of coverage of the map to other SNOMED CT concepts (e.g. concepts outside the priority list or within the U.S. Extension to SNOMED CT) will depend on user feedback and availability of resources.
Release schedule
A preview release of a subset of the Map was published in February, covering 7, 277 SNOMED CT concepts. The final release of the Phase 1 Map is now available, covering 15,613 concepts. The Map will be periodically maintained and updated to synchronize with changes in the two terminologies.
File format
The Map is published primarily as four refsets in the SNOMED CT Release Format 2 (RF2) format. To support easy browsing and understanding of the Map, it is also published as a tab delimited file that can be opened as a spreadsheet. This is a “readable” version of the Map that can be understood by a non-technical individual.
License requirements
In accordance with NLM’s mapping assumptions, the Map can be used by users that are licensed to use both SNOMED CT and ICD-10-CM. SNOMED CT is owned by the International Health Terminology Standards Development Organisation (IHTSDO), of which NLM is the US Member. Use of SNOMED CT is free in IHTSDO Member countries including the United States, in low income countries, and for approved research projects in any country, but is subject to the IHTSDO Affiliate license provisions ( incorporated in the License Agreement for Use of the UMLS® Metathesaurus® as Appendix 2). The use of ICD-10-CM is free in the US. Users in other countries may need to contact WHO for the use of ICD-10-CM.
Comments and questions
We welcome any questions, comments or suggestions that would improve the quality, accuracy and usability of the Map. Please send feedback to Dr. Kin Wah Fung, Lister Hill National Center for Biomedical Communications, National Library of Medicine through NLM Customer Service with the subject line “SNOMED CT to ICD-10-CM Map”.
Acknowledgements
We thank Dr. James Campbell (University of Nebraska) and Dr. David Berglund (National Center for Health Statistics in the Centers for Disease Control and Prevention) for their contributions to the project. We made significant use of mapping data previously produced by the IHTSDO and the UK National Health Service (NHS) Terminology Centre, which provided access to data and tools from the SNOMED CT to ICD-10 Crossmap Project, and Kaiser Permanente, which included basic mappings to ICD-10-CM in some of their CMT content. We thank the IHTSDO, the UK NHS Terminology Centre, and Kaiser Permanente for these contributions, which significantly reduced the resources and time required to produce the SNOMED CT to ICD-10-CM Map. We also thank CAP SNOMED Terminology Solutions Professional Services of the College of American Pathologists for their review of a subset of the Map and useful feedback.
