Diseases of the circulatory system (I00–I99) ICD-10-CM
Chapter 9 of the ICD-10-CM classification spans codes I00–I99 and contains 1,807 diagnosis codes for diseases of the circulatory system, of which 1,433 are billable. The chapter is organized into 10 sections listed below, each linking to its code ranges and individual codes.
Chapter Coding Notes
Excludes2: certain conditions originating in the perinatal period (P04-P96), certain infectious and parasitic diseases (A00-B99), complications of pregnancy, childbirth and the puerperium (O00-O9A), congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99), endocrine, nutritional and metabolic diseases (E00-E88), injury, poisoning and certain other consequences of external causes (S00-T88), neoplasms (C00-D49), symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94), systemic connective tissue disorders (M30-M36), transient cerebral ischemic attacks and related syndromes (G45.-)
Sections in This Chapter 10 ranges · 1,807 codes
The info icon previews the code ranges inside each row and its instructional notations from the official Tabular List.
About Chapter 9
Heart diseases and disorders of blood vessels, lymphatic vessels, and lymph nodes appear here. The chapter also includes diseases involving circulation through the lungs and conditions affecting the brain’s blood vessels.
The groups begin with acute rheumatic fever and chronic rheumatic heart disease, then separate hypertensive diseases from ischemic heart diseases. Other groups distinguish pulmonary heart disease and pulmonary circulation diseases, other forms of heart disease, and cerebrovascular diseases. The final groups separate artery and smaller-vessel diseases from vein and lymphatic disorders, followed by other or unspecified circulatory disorders.
FY 2027 changes: The FY 2027 ICD-10-CM update, effective October 1, 2026, added 9 codes and deleted 3 codes in this chapter.
Questions About This Page
How many codes are in the I00-I99 range?
The I00-I99 range contains 1,807 ICD-10-CM diagnosis codes in FY 2027. 1,433 of them are billable, and the rest are category headers that organize the chapter.
What conditions does I00-I99 cover?
The range covers diseases of the circulatory system. The sections listed above break it into groups of related conditions, and each one links to its own page with the full code list.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
