icd-10 icd-10 icd-10 is the 10th revision of the international statistical classification of diseases and related health problems (icd), a medical classification list by the world health organization (who). it contains codes for diseases, signs and symptoms, abnormal findings, complaints, social circumstances, and external causes of injury or diseases. work on icd-10 began in 1983, became endorsed by the forty-third world health assembly in 1990, and was first used by member states in 1994. it was replaced by icd-11 on january 1, 2022. international classification of diseases version 10international statistical classification of diseases and related health problems 10th revisionabbreviationicd-10statusactiveyear started1983first published1994preview version1990organizationworld health organizationdomainmedical classificationwebsiteicd.who.int/browse10/2019/en while who manages and publishes the base version of the icd, several member states have modified it to better suit their needs. in the base classification, the code set allows for more than 14,000 different codes and permits the tracking of many new diagnoses compared to the preceding icd-9. through the use of optional sub-classifications, icd-10 allows for specificity regarding the cause, manifestation, location, severity, and type of injury or disease. the adapted versions may differ in a number of ways, and some national editions have expanded the code set even further; with some going so far as to add procedure codes. icd-10-cm, for example, has over 70,000 codes. the who provides detailed information regarding the icd via its website – including an icd-10 online browser and icd training materials. the online training includes a support forum, a self-learning tool and user guide. chapters the following table lists the chapter number (using roman numerals), the code range of each chapter, and the chapter's title from the international version of the icd-10. icd-10 chapters chapter block title i a00–b99 certain infectious and parasitic diseases ii c00–d48 neoplasms iii d50–d89 diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism iv e00–e90 endocrine, nutritional and metabolic diseases v f00–f99 mental and behavioural disorders vi g00–g99 diseases of the nervous system vii h00–h59 diseases of the eye and adnexa viii h60–h95 diseases of the ear and mastoid process ix i00–i99 diseases of the circulatory system x j00–j99 diseases of the respiratory system xi k00–k93 diseases of the digestive system xii l00–l99 diseases of the skin and subcutaneous tissue xiii m00–m99 diseases of the musculoskeletal system and connective tissue xiv n00–n99 diseases of the genitourinary system xv o00–o99 pregnancy, childbirth and the puerperium xvi p00–p96 certain conditions originating in the perinatal period xvii q00–q99 congenital malformations, deformations and chromosomal abnormalities xviii r00–r99 symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified xix s00–t98 injury, poisoning and certain other consequences of external causes xx v01–y98 external causes of morbidity and mortality xxi z00–z99 factors influencing health status and contact with health services xxii u00–u99 codes for special purposes national adoptions approximately 27 countries use icd-10 for reimbursement and resource allocation in their health system, and some have made modifications to icd to better accommodate its utility. the unchanged international version of icd-10 is used in 117 countries for performing cause of death reporting and statistics. the national versions may differ from the base classification in the level of detail, incomplete adoption of a category, or the addition of procedure codes. australia introduced in 1998, icd-10 australian modification (icd-10-am) was developed by the national centre for classification in health at the university of sydney. it is currently maintained by the australian consortium for classification development. icd-10-am has also been adopted by new zealand, the republic of ireland, saudi arabia and several other countries. brazil brazil introduced icd-10 in 1996. canada canada began using icd-10 for mortality reporting in 2000. a six-year, phased implementation of icd-10-ca for morbidity reporting began in 2001. it was staggered across canada's ten provinces, with quebec the last to make the switch. icd-10-ca is available in both english- and french-language versions. china china adopted icd-10 in 2002. czech republic the czech republic adopted icd-10 in 1994, one year after its official release by who. revisions to the international edition are adopted continuously. the official czech translation of icd-10 2016 10th revision was published in 2018. denmark icd-10 was first introduced into the psychiatric health service system on 1 january 1994. estonia estonia adopted icd-10 from january 1, 1997, via a ministerial degree. however, chapter v "mental and behavioural disorders" had already been in use from january 1, 1994, also via a ministerial degree. france france introduced a clinical addendum to icd-10 in 1997.