Quick answer: ICD-10 codes for heart disease are standardized diagnosis codes doctors and hospitals use to document and bill for cardiovascular conditions. Heart disease sits in the range I00 to I99 of the ICD-10-CM manual, with ischemic heart disease at I20 to I25, heart failure at I50, hypertensive heart disease at I11, and atrial fibrillation at I48. A family history of heart disease is coded separately, as Z82.49. None of this is the same thing as an ICD device — an implantable cardioverter-defibrillator, which is a different piece of equipment that happens to share the same three-letter abbreviation. This page covers the coding system; see the note below if you were looking for the device.
Not the Same Thing: ICD-10 Codes vs. an ICD Device
“ICD” means two different things in cardiology, and mixing them up is a common source of confusion.
- ICD-10 (International Classification of Diseases, 10th Revision) is a coding system published by the World Health Organization and maintained in the US as ICD-10-CM. It assigns a short alphanumeric code to every diagnosis, from a heart attack to a broken toe, so that medical records, insurance claims and public health statistics can all refer to the same condition consistently.
- An ICD in the sense of a medical device is an implantable cardioverter-defibrillator — a small battery-powered device placed under the skin near the collarbone, with wires running into the heart, that monitors heart rhythm and delivers a shock if it detects a dangerous arrhythmia such as ventricular fibrillation. It is used in people who have survived cardiac arrest or are at high risk of one.
A person who has an implantable defibrillator will also have an ICD-10 diagnosis code documenting the condition that led to it — but the device and the code are not the same thing, and neither implies the other. If you were looking for information about the defibrillator device itself rather than diagnosis coding, that is a different topic from what this page covers.
How the Coding Range Is Organized
Heart and blood vessel conditions sit within Chapter 9 of ICD-10-CM, “Diseases of the circulatory system,” coded I00 through I99. The heart-specific ranges within it are:
| Code range | Covers |
|---|---|
| I10 to I16 | Hypertensive diseases, including hypertensive heart disease |
| I20 to I25 | Ischemic heart diseases: angina, heart attack, chronic coronary artery disease |
| I26 to I28 | Pulmonary heart disease and diseases of the pulmonary circulation |
| I30 to I5A | Other forms of heart disease: valve disorders, cardiomyopathy, arrhythmias, heart failure |
| I60 to I69 | Cerebrovascular disease, including stroke |
Frequently Used Codes
A working sample of the codes clinicians and coders use most often for cardiovascular diagnoses:
| Code | Diagnosis |
|---|---|
| I10 | Essential (primary) hypertension |
| I11.0 | Hypertensive heart disease with heart failure |
| I11.9 | Hypertensive heart disease without heart failure |
| I20.9 | Angina pectoris, unspecified |
| I21.0 to I21.4 | Acute myocardial infarction (STEMI and NSTEMI, by site) |
| I25.10 | Atherosclerotic heart disease of a native coronary artery, without angina |
| I48.0 to I48.2 | Atrial fibrillation, by pattern (paroxysmal, persistent, chronic) |
| I50.9 | Heart failure, unspecified |
| I50.2x / I50.3x | Systolic / diastolic (congestive) heart failure, by acuity |
Each of these has more specific sub-codes in practice — I21, for example, branches into which coronary artery territory the heart attack affected. Coders select the most specific code the documentation supports rather than defaulting to an unspecified code.
Family History of Heart Disease: Z82.49
A family history of heart disease is documented differently from a personal diagnosis. Z82.49 (“family history of ischemic heart disease and other diseases of the circulatory system”) is used when a close relative — a parent, sibling or grandparent — has had a circulatory condition, and that history is relevant to the current patient’s risk assessment or care plan.
This code does not mean the patient has heart disease themselves. It flags a risk factor, and it cannot be used as the main reason for a visit on its own — it is recorded alongside the actual reason for the encounter.
Why the Code Matters Beyond Billing
- Insurance and billing. Claims are processed against the specific code submitted, and a vague or wrong code is a common reason for a denied or delayed claim.
- Continuity of care. Codes let different providers and hospital systems recognize the same diagnosis consistently in a shared record.
- Public health tracking. National statistics on how common each type of heart disease is, and how outcomes change over time, are built from coded diagnosis data.
Frequently Asked Questions
There is no single code, because heart disease covers many distinct conditions. The overall circulatory-system chapter is I00 to I99, ischemic heart disease is I20 to I25, hypertensive heart disease is I11, heart failure is I50, and atrial fibrillation is I48. A doctor or coder selects the specific code that matches the diagnosis actually documented.
No. ICD-10 is a diagnosis coding system used for medical records and billing. An implantable cardioverter-defibrillator is a physical device placed in the chest to treat dangerous heart rhythms. They share the same three-letter abbreviation, ICD, but are otherwise unrelated. A person with a defibrillator device also has an ICD-10 code documenting the condition that led to it, but the device and the code are two different things.
Z82.49, family history of ischemic heart disease and other diseases of the circulatory system. It documents that a close relative has had a circulatory condition and is used as a risk factor alongside the actual reason for a visit, not as a diagnosis of the patient themselves.
I11, which splits into I11.0 (with heart failure) and I11.9 (without heart failure). This is distinct from I10, essential hypertension without heart involvement, and from the ischemic heart disease codes at I20 to I25, which cover coronary artery disease rather than hypertension-driven heart changes.
Trained medical coders assign the codes, based on the diagnosis documented by the treating clinician in the medical record. The codes themselves are maintained and updated annually by the World Health Organization internationally and by the Centers for Medicare and Medicaid Services and the National Center for Health Statistics for the US version, ICD-10-CM.
Sources
- CDC / National Center for Health Statistics — ICD-10-CM.
- Centers for Medicare and Medicaid Services — ICD-10 codes.
- World Health Organization — Classification of Diseases (ICD).
- MedlinePlus — Implantable cardioverter-defibrillator.
Last updated: August 2026. This article is general information about medical coding, not medical or billing advice for a specific claim. Coding decisions should be made by a qualified medical coder based on the actual documentation in the patient’s record, and disputed claims should be discussed with the billing office and insurer directly.
