I.C.9.e.6)

Myocardial Infarction with Coronary Microvascular Dysfunction

Coronary microvascular dysfunction (CMD) is a condition that impacts the microvasculature by restricting microvascular flow and increasing microvascular resistance.

Code I21.B, Myocardial infarction with coronary microvascular dysfunction, is assigned for myocardial infarction with coronary microvascular disease, myocardial infarction with coronary microvascular dysfunction, and myocardial infarction with non-obstructive coronary arteries (MINOCA) with microvascular disease.

ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026 (effective October 1, 2025). Published by CMS and NCHS. Reproduced for reference — always verify against the official CMS release.