ICD-10International Classification of Diseases, 10th Revision
In short
ICD-10 is the tenth revision of WHO's International Classification of Diseases: an ordered list of coded categories for recording diseases, health problems and causes of death. For decades it has underpinned mortality and morbidity statistics and many payment systems. Its successor, ICD-11, has been in effect since 2022, but ICD-10 and its national modifications remain widely used.
- Type
- Terminology
- Current version
- 2019
- Reviewed
- October 25, 2026
Explanation
What it is
The International Classification of Diseases (ICD) has been the basis for comparable mortality and morbidity statistics between countries and over time for more than a century. WHO maintains it under its Constitution. The tenth revision was adopted by the World Health Assembly in May 1990 (resolution WHA43.24) and came into effect on 1 January 1993. The latest version WHO offers in its ICD-10 browser is the 2019 version.
What it is used for
According to WHO, ICD-coded data are used to:
- certify and analyse causes of death;
- record morbidity in primary, secondary and tertiary care;
- group cases for diagnosis-related group (DRG) payments and resource allocation;
- monitor quality and safety of care, and feed cancer registries and research.
National modifications
Several countries adapted ICD-10 for clinical and billing use. In the US, on 1 October 2015 the health care industry moved from ICD-9 to ICD-10 for diagnoses (ICD-10-CM, updated by the National Center for Health Statistics, NCHS) and inpatient procedures (ICD-10-PCS). The transition applies to all parties covered by HIPAA, not just those who bill Medicare or Medicaid.
Relationship with ICD-11
ICD-11 came into effect on 1 January 2022. WHO notes that all Member States have committed to using the most recent version of ICD, and it publishes mapping tables to ease the transition. Meanwhile, many statistics and payment systems still run on ICD-10 or on national modifications.
Common misconceptions
- ICD-10 is a statistical classification, not a detailed clinical terminology. Fine-grained clinical recording uses terminologies such as SNOMED CT.
- A national modification is not WHO's ICD-10. ICD-10-CM, for example, has its own codes and rules.
- Maps from SNOMED CT help with coding, but they do not fully automate code assignment.
- State the version. WHO activated new codes after 1993, for example the emergency-use codes for COVID-19 in 2020.
Usage examples
In the US, since 1 October 2015 diagnoses have been coded with ICD-10-CM and inpatient procedures with ICD-10-PCS, and the requirement covers all parties covered by HIPAA.
In Brazil, the Ministry of Health's Mortality Information System (SIM) codes causes of death with ICD-10, version 2019; in 2025 the ministry published a booklet that guides the coding of deaths with U07.0 (e-cigarette-related disease), a WHO emergency-use code.
In February 2020, WHO activated ICD-10 emergency codes for confirmed COVID-19 and for suspected or probable COVID-19.
Between 2023 and 2024, WHO released three versions of a map between ICD-10 and the MedDRA dictionary, used to report drug-related information.
SNOMED International publishes a SNOMED CT to ICD-10 map to help derive ICD-10 codes from the coded health record.
A death certificate records the chain of causes as text, and a coder assigns the underlying cause using ICD-10 selection rules.
Relation to other terms
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Sources
- WHO — International Classification of Diseases (ICD)who.int
- WHO — ICD-10 Version:2019 (navegador)icd.who.int
- WHO — Emergency use ICD codes for COVID-19 disease outbreakwho.int
- CMS — ICD-10 Codescms.gov
- Ministério da Saúde (Brasil, 2025), cartilha — Codificação das causas de morte com menção da doença relacionada ao uso de cigarro eletrônicogov.br
- SNOMED CT to ICD-10 Map Specification — ICD-10 Map Overviewdocs.snomed.org