ICD-10-CM > I00-I99 > I20-I25 > I20 > I20.8 I20.8 Other forms of angina pectoris Non-Billable/Non-Specific Use Additional code(s) for symptoms associated with angina equivalent Codes I20.81Angina pectoris with coronary microvascular dysfunctionI20.89Other forms of angina pectoris