ICD-10-CM > I00-I99 > I20-I25 > I20 I20 Angina pectoris Non-Billable/Non-Specific Use Additional code to identify:exposure to environmental tobacco smoke (Z77.22)history of tobacco dependence (Z87.891)occupational exposure to environmental tobacco smoke (Z57.31)tobacco dependence (F17.-)tobacco use (Z72.0) Type 1 Excludes angina pectoris with atherosclerotic heart disease of native coronary arteries (I25.1-)atherosclerosis of coronary artery bypass graft(s) and coronary artery of transplanted heart with angina pectoris (I25.7-)postinfarction angina (I23.7) Codes I20.0Unstable anginaI20.1Angina pectoris with documented spasmI20.2Refractory angina pectorisI20.8Other forms of angina pectorisI20.81Angina pectoris with coronary microvascular dysfunctionI20.89Other forms of angina pectorisI20.9Angina pectoris, unspecified