The fiscal year 2027 ICD-10-CM classification contains 98,403 diagnosis codes, of which 74,879 are billable, organized into 22 chapters. Each chapter below links to its sections, code ranges, and individual codes, and the info icons preview what each chapter contains.
✓ Built from the official CMS FY 2027 datasetEffective Oct 1, 2026 – Sep 30, 2027
The info icon previews the code ranges inside each row and its instructional notations from the official Tabular List.
Questions About This Page
How many ICD-10-CM codes are there in FY 2027?
The FY 2027 classification contains 98,403 diagnosis codes across 22 chapters. Of these, 74,879 are billable codes specific enough to submit on claims, and the rest are category headers that group them.
How is the ICD-10-CM code set organized?
Codes are grouped first by chapter, which covers a body system or type of condition, then by section, a range of related categories, and finally by three character category. Every level on this page links one step deeper until you reach the individual code.
Which chapter has the most codes?
Injury, poisoning and certain other consequences of external causes (S00–T88) is the largest chapter with 54,325 codes, driven by the characters that carry laterality, encounter type, and other detail.
