❤️ Chapter 9 · I00-I99

Heart & Circulation Diagnosis Codes

Circulatory system codes are among the most frequently used in healthcare. They cover hypertension, heart failure, coronary artery disease, stroke, and vascular conditions. Because cardiovascular disease is the leading cause of death in the US, precise coding is critical for treatment planning.

About This Chapter

Chapter 9 of the ICD-10-CM classification covers diseases of the circulatory system, spanning codes I00-I99. These codes are used by healthcare providers to document diagnoses in your electronic health record (EHR), on insurance claims, and on medical bills.

Why this matters: If you see a code starting with I on your medical bill or health records, it likely falls in this chapter. Understanding what chapter your code belongs to can help you make sense of your diagnosis and ask better questions at your next appointment.

Diagnosis Codes in This Chapter

Browse the 44 diagnosis codes we currently cover in this chapter. Select any code to read a plain-English explanation.

I10Essential Hypertension I11.9Hypertensive Heart Disease I20.9Angina Pectoris I21.9Acute Myocardial Infarction (Heart Attack)... I24.9Acute Ischemic Heart Disease I25.10Coronary Artery Disease I25.119Atherosclerotic Heart Disease with Angina... I26.02Saddle Embolus of Pulmonary Artery... I26.99Pulmonary Embolism Without Acute Cor Pulmo... I27.0Primary Pulmonary Hypertension I31.9Disease of Pericardium I34.0Mitral Valve Insufficiency I35.0Aortic Valve Stenosis I42.9Cardiomyopathy, Unspecified I44.1Atrioventricular Block, Second Degree... I45.10Right Bundle-Branch Block I47.1Supraventricular Tachycardia I48.0Paroxysmal Atrial Fibrillation I48.1Persistent Atrial Fibrillation I48.2Chronic Atrial Fibrillation I48.91Atrial Fibrillation I49.9Cardiac Arrhythmia, Unspecified I50.22Chronic Systolic Heart Failure I50.32Chronic Diastolic Heart Failure I50.9Heart Failure, Unspecified I50Heart Failure I51.9Heart Disease, Unspecified I60.9Subarachnoid Hemorrhage I61.9Intracerebral Hemorrhage I63.9Cerebral Infarction (Stroke) I65.29Occlusion of Carotid Artery I67.9Cerebrovascular Disease, Unspecified... I69.30Sequelae of Cerebral Infarction I70.0Atherosclerosis of Aorta I71.4Abdominal Aortic Aneurysm I73.9Peripheral Vascular Disease I77.1Stricture of Artery I80.10Phlebitis of Femoral Vein I82.401Deep Vein Thrombosis, Right Leg... I82.409Deep Vein Thrombosis, Unspecified... I83.90Varicose Veins of Lower Extremities... I87.2Venous Insufficiency I89.0Lymphedema I95.1Orthostatic Hypotension