The U.S. Department of Health and Human Services (HHS) issued a rule in Federal Register Vol. 79, No. 149 that finalized October 1, 2015, as the compliance date for health care providers, health plans, and health care clearinghouses to use ICD-10, the tenth revision of the International Classification of Diseases. The rule required HIPAA covered entities to continue to use ICD-9-CM through September 30, 2015. The diagnosis code used will be based on date of service.

See the CMS ICD-10 webpage for many different resources regarding the transition to ICD-10 and ongoing maintenance of the ICD-10 codes.