Angina Pectoris ICD-10-CM codes

Category I20 is used only when angina is not linked to coronary atherosclerosis. I20.0 is unstable angina, I20.1 is angina with documented spasm (Prinzmetal or variant angina), I20.2 is refractory angina, I20.81 is angina with coronary microvascular dysfunction, I20.89 covers other forms including stable angina, and I20.9 is angina unspecified.

When the patient also has coronary artery disease, the official guidelines presume a causal relationship and require a combination code instead of I20. For native coronary arteries use I25.11-: I25.110 (unstable), I25.111 (with spasm), I25.112 (refractory), I25.118 (other forms), or I25.119 (unspecified angina). The I25.7- codes serve the same purpose for bypass grafts and transplanted hearts. Do not report an I20 code together with an I25.11- or I25.7- code.

An acute MI takes precedence over angina: when both are documented during the same episode, code the I21 code and not the angina. Angina that follows an MI within 28 days is postinfarction angina, I23.7. Chest pain not diagnosed as angina stays in chapter 18 (R07.9 or R07.89), so do not assign I20.9 from chest pain alone.