Adoption of ICD-10-CM was slow in the United States. Since 1979, the US had required ICD-9-CM codesInternational Classification Of Diseases - 9 - CM, (1979). Wonder.cdc.gov. Retrieved on 2014-06-20. for Medicare and Medicaid claims, and most of the rest of the American medical industry followed suit. On 1 January 1999 the ICD-10 (without clinical extensions) was adopted for reporting mortality, but ICD-9-CM was still used for morbidity. Meanwhile, the U.S. National Center for Health Statistics (NCHS) received permission from the WHO to create a clinical modification of the ICD-10, and has production of all these systems:
