CAD ICD 10: Coronary Artery Disease Codes and Coding Rules

The CAD ICD 10 code is I25.10, which identifies atherosclerotic heart disease of the native coronary artery without angina pectoris. If CAD and angina are documented, use the appropriate combination code, such as I25.110 for unstable angina or I25.119 for unspecified angina. Bypass-graft disease follows a separate coding pathway.

Check the diagnosed condition, then review angina status and the affected vessel. Chest discomfort alone, a coronary stent or a history of CABG cannot answer those questions.

This reference explains ICD-10-CM coding for use in the United States. Coding classifications used in other countries may differ. CDC’s National Center for Health Statistics maintains the U.S. clinical modification.

Quick-reference table for CAD ICD-10 coding

The descriptions below use plain language. Verify the full descriptor, inclusion terms and inherited instructions in the official Tabular List.

I25.11 and I25.7 are subdivided headings, not complete codes to submit in place of the required child codes. This table includes some, but not all, of the codes in the I25 family. The distinctions follow the official CDC code tables.

I25.10 meaning: native coronary disease without angina

I25.10 represents atherosclerotic disease of the native coronary arteries without angina pectoris. “Native” refers to the coronary arteries themselves, as distinct from surgically created bypass grafts. It doesn’t imply that the patient has never undergone an intervention.

A stented native artery is still a native artery. Likewise, a patient may have disease in the native coronary arteries after CABG. A procedure history does not automatically place the CAD diagnosis in a graft category.

The Alphabetic Index directs coronary artery disease to the atherosclerotic ischemic-heart-disease pathway. If CAD is documented without further qualifying information, I25.10 may be the indexed default. You’ll still need to review the complete record for angina, graft involvement or another specifically documented condition.

Don’t consider I25.10 a less appropriate code simply because it doesn’t include an angina subtype. If it accurately describes the documented disease, replacing it with a more severe diagnosis would make the claim less accurate.

Stable CAD and stable angina are different descriptions. The term “CAD, stable” does not establish an angina diagnosis. The provider may be indicating that the underlying disease is controlled. “CAD with stable angina” supplies additional diagnostic information and supports a different code.

Atherosclerotic heart disease and other ischemic diseases

Plaque buildup in the coronary arteries is common in CAD. According to the American Heart Association, this buildup can limit blood flow to the heart muscle. That background helps readers understand the terminology, but it cannot replace the provider’s diagnosis.

Don’t treat every phrase containing “heart disease” as interchangeable. I25.9 describes chronic ischemic heart disease, unspecified. It isn’t a universal replacement for documented coronary atherosclerosis or a placeholder for suspected CAD.

Follow the actual diagnostic wording through the Index. Broad terminology for ischemic heart disease and a specific diagnosis of coronary atherosclerosis can lead to different entries.

ICD-10 coding for CAD with angina

When atherosclerotic CAD and angina are both documented, ICD-10-CM generally presumes a causal relationship unless the record states that the angina has another cause. The appropriate combination code represents both conditions.

Don’t add a separate I20 code for angina already captured by that combination code. Also review the exception when the provider explicitly documents an unrelated cause.

This presumption connects two documented diagnoses. It does not establish angina based solely on nitroglycerin use, breathlessness or chest pain.

Stable and other specified angina: I25.118

I25.118 applies to native-coronary atherosclerotic disease with other forms of angina, including stable angina when supported by the indexed diagnosis.

“Other forms” does not mean “type unknown.” A specified form of angina without a more specific combination code is different from angina whose type has not been documented.

This distinction matters when an assessment identifies controlled stable angina but the symptom review records no chest discomfort. A symptom-free examination does not automatically cancel a documented angina condition that remains under treatment. Read the assessment and treatment plan together before deciding that the documentation conflicts.

Unstable angina: I25.110

I25.110 identifies native-coronary atherosclerosis with unstable angina. Don’t use I25.118 for documented unstable angina simply because a general reference describes it as another form of angina.

The diagnosis must come from the responsible provider. Severe pain, an urgent presentation or an abnormal test does not independently support assigning this code.

If the provider establishes an acute myocardial infarction, apply the MI coding rules rather than using unstable angina as a substitute. An elevated troponin result also requires clinical interpretation; it does not establish the diagnosis by itself.

Spasm, refractory angina and unspecified angina

Use I25.111 when the diagnosis supports native-coronary atherosclerosis with angina and documented spasm. I25.112 identifies refractory angina associated with native-coronary atherosclerosis.

“Refractory” and “unstable” are not synonymous. Don’t assign refractory angina simply because the medication list is extensive or the symptoms seem difficult to control.

I25.119 applies when CAD and angina are documented but the type of angina is unspecified. If the record contains conflicting or incomplete information, a focused clarification may help. When greater specificity cannot be established, report the supported diagnosis without inventing a subtype.

Native artery, bypass graft and transplanted-heart disease

A surgical history tells you which procedure took place. It doesn’t always identify which vessel has atherosclerosis in the encounter you’re coding.

Before selecting a graft code, distinguish the native artery from the bypass conduit. If graft disease is documented, identify the affected graft type where relevant and determine whether angina is present.

CAD after CABG

Previous CABG does not automatically establish active bypass-graft atherosclerosis. Z95.1 identifies the presence of an aortocoronary bypass graft. It does not describe plaque disease in the graft.

One record may support native-vessel CAD and CABG status while the grafts remain patent. Another may identify atherosclerosis in a bypass graft. The patients may have undergone the same operation, but their coding circumstances differ.

If both native arteries and bypass grafts have documented, reportable disease, review the applicable codes and instructions for each site. Don’t duplicate a disease code merely to capture the surgical history.

Graft disease with or without angina

I25.810 identifies coronary bypass-graft atherosclerosis without angina. It is not limited to transplanted hearts.

The I25.7 family classifies coronary atherosclerosis involving bypass grafts or transplanted hearts when angina is present. Within the graft categories, codes distinguish autologous vein, autologous artery, nonautologous biological and other graft types.

For example, I25.700 describes graft atherosclerosis with unstable angina when the graft type is unspecified. If the affected graft is documented as an autologous vein graft, I25.710 captures that detail.

If the patient has more than one conduit, don’t infer the diseased graft type from a general CABG history. The record should identify the affected structure rather than simply list all grafts placed.

Transplanted-heart coronary disease

Without angina, I25.811 identifies disease in the native coronary arteries of a transplanted heart. I25.812 identifies disease in a coronary bypass graft of a transplanted heart.

“Native” refers to the arteries native to the transplanted heart. This wording can be difficult to interpret when you’re reading only an abbreviated code description.

Transplant-related complications require their own documentation and review of applicable instructions. Don’t automatically add a complication code because a patient has a heart transplant, or use a transplant-status code in place of documented active disease.

History of CAD ICD-10: active disease, status or resolved condition?

The phrase “history of CAD” requires context. Clinicians sometimes use “history” to describe a previously diagnosed disease that remains under management. Coding conventions for personal history are more limited.

Review whether the provider continues to assess or manage CAD, whether the note describes a resolved condition, or whether the phrase simply introduces previous procedures. If the assessment is unclear, seek clarification rather than letting an EHR history heading determine the code.

Z86.79 describes personal history of other diseases of the circulatory system. It should not replace active CAD simply because the patient has no symptoms or has undergone revascularization.

Old MI is a separate consideration. I25.2 represents an old or healed myocardial infarction and does not automatically replace CAD. Both diagnoses may be reported when supported by the record and the encounter’s reporting rules.

Keep these questions distinct during review. A previous heart attack and active coronary atherosclerosis describe different aspects of the patient’s condition.

Coding guidelines, exclusion notes and additional instructions

A code means more than its description alone. Instructions may appear at the individual code, parent category or broader block. Review those levels before finalizing a claim.

Excludes1: avoid incompatible reporting

An Excludes1 note generally prohibits reporting the excluded condition with the code above the note. A limited exception applies when the conditions are unrelated. If their relationship is unclear, seek clarification.

For CAD, I25.110 excludes unstable angina without atherosclerotic heart disease, I20.0. I25.119 similarly excludes unspecified angina without atherosclerotic heart disease, I20.9.

The practical result is straightforward: don’t report I25.110 and I20.0 for the same atherosclerotic unstable-angina condition.

The graft categories also distinguish disease with angina from disease without angina. Don’t report I25.810 alongside an angina-containing graft code merely to describe the same graft disease twice.

Excludes2: distinct conditions may coexist

An Excludes2 note means that the excluded condition is not included in the code, although both may be reported when appropriate.

I25.1 lists graft and transplanted-heart atherosclerosis from I25.7 under Excludes2. This allows documented native disease and separately documented graft disease to be considered individually, rather than assuming that one automatically excludes the other.

I25 also lists non-ischemic myocardial injury, I5A, under Excludes2. That does not justify inferring myocardial injury from a laboratory result. Both diagnoses must be established and meet the applicable reporting requirements.

“Code first” and “use additional code”

I25.82 identifies chronic total coronary occlusion. Its code-first instruction directs the coder to report the coronary atherosclerosis first.

I25.83, for lipid-rich plaque, and I25.84, for a calcified coronary lesion, also carry code-first instructions for coronary atherosclerosis. These codes provide additional documented detail; they do not replace the underlying CAD classification.

Don’t assume that an isolated calcium score establishes a specific CAD subtype without reviewing the provider’s interpretation and applicable coding guidance. If the report and assessment leave the diagnosis unclear, clarification may be needed.

The I25 category also includes additional-code instructions for applicable tobacco use, dependence, history and exposure. Report the category supported by the record rather than adding every available tobacco-related code.

“Code also” and associated hypertension

The ischemic-heart-disease block instructs coders to code associated hypertension. The “code also” instruction does not, by itself, determine sequencing.

Select the hypertension code supported by the complete record and relevant hypertension guidelines. Before assigning I10, check whether another hypertensive classification applies.

Associated diabetes or heart failure also requires separate review. The presence of several conditions in the same chart does not automatically place them in one combination code.

Related diagnoses that should not be folded into I25.10

Acute MI and ischemic cardiomyopathy

Acute myocardial infarction is a separate condition from chronic CAD. When the admission is primarily for an acute MI, follow the official sequencing guidelines and report the MI before CAD when the coding rules require it.

Ischemic cardiomyopathy, coded as I25.5, also requires separate provider documentation. A history of CAD or a reduced ejection fraction doesn’t allow the coder to assign ischemic cardiomyopathy independently. Any documented heart failure should be reviewed and coded under the applicable guidelines.

Hospital Medical Billing Services teams should avoid building a diagnosis from clinical clues alone. Test results, medication history, and past CAD documentation may support a provider query, but they cannot replace the provider’s documented assessment.

Coronary microvascular dysfunction

Disease involving the coronary microvasculature requires separate consideration. I25.85 identifies chronic coronary microvascular dysfunction, while I20.81 identifies angina pectoris with coronary microvascular dysfunction.

Neither is an automatic synonym for native-coronary atherosclerosis. Follow the documented microvascular diagnosis through the Index, particularly when the record also mentions angina, infarction or obstructive disease.

This distinction helps prevent a broad CAD label from obscuring the condition the clinician actually diagnosed.

A practical CAD ICD-10 coding workflow

Use this sequence to guide your review alongside the official classification.

1. Determine the purpose of the encounter. Distinguish symptom evaluation from management of confirmed disease or treatment of an acute event.
2. Read the provider’s final assessment. Identify the established diagnosis rather than relying on a copied problem-list code.
3. Check the affected vessels. Identify native coronary arteries, bypass grafts or transplanted-heart coronary vessels.
4. Review angina documentation. Confirm whether angina is diagnosed and whether a supported subtype is specified.
5. Use the Index and Tabular List. Verify the complete code and all applicable parent-level instructions.
6. Review additional diagnoses and status. Report information that meets the applicable reporting requirements.
7. Check the claim separately. Review code validity, sequencing, diagnosis pointers, procedure documentation and payer requirements.

The CDC’s coding browser lets you move between Index and Tabular entries. This is helpful when a search result provides a familiar code but omits the instructions attached to it.

Outpatient uncertainty requires care

Don’t report suspected or rule-out CAD as confirmed in outpatient settings. Code to the supported level of certainty, which may be a symptom, finding or another established diagnosis.

Inpatient uncertain-diagnosis rules differ. Don’t apply an inpatient discharge convention to an office encounter, emergency-department visit or observation service.

A practice can reduce confusion by identifying the care setting at the beginning of its review template. Otherwise, staff may agree on the clinical wording while applying different reporting rules.

Documentation tips for providers and coding teams

Good documentation uses clinical language to describe the patient’s condition. It doesn’t need to read like a codebook.

When the affected vessel or graft is known, identify it. Describe diagnosed angina rather than relying solely on the symptom review. If established angina remains controlled with medication, make that assessment clear.

Distinguish active disease from procedural status. Native-vessel CAD without angina and a coronary stent present is different from in-stent restenosis or atherosclerosis of a vein bypass graft.

When documentation conflicts, identify the actual discrepancy. Treated stable angina and a symptom-free review of systems are not automatically inconsistent. An assessment of “no angina” alongside another assessment of “unstable angina” may need closer review.

Useful details to clarify include:

• The active diagnosis being evaluated or managed.
• Native-vessel or graft involvement.
• The affected graft type, when known.
• The angina subtype, if clinically established.
• Whether a condition has resolved or remains active.
• Any documented relationship between a suspected complication and an implant or procedure.
• Relevant coexisting conditions addressed during the encounter.

A neutral provider-query approach

AHIMA and ACDIS emphasize clinical indicators, nonleading wording and independent provider judgment. A query should resolve documentation without directing the clinician toward a payment outcome.

For conflicting angina documentation, an open-ended request could read:

The assessment identifies native-coronary CAD without angina, while the cardiology assessment identifies stable angina. Please clarify the diagnosis applicable to this encounter and reconcile these entries. If the relationship or diagnosis cannot be determined, please document that.

This is an illustrative prompt rather than a universal template. Include the actual conflicting entries and relevant context. If you use multiple-choice options, ensure that they are clinically reasonable and allow other explanations or an inability to determine the diagnosis.

Don’t request an unstable-angina diagnosis solely because a risk-adjustment model classifies it differently.

Three realistic coding scenarios

These are hypothetical teaching examples, not patient records or claims of personal clinical experience. They focus on the CAD coding decision; a complete claim may require other supported codes.

Scenario 1: Native CAD with a coronary stent present

The cardiologist documents native-coronary atherosclerosis without angina and continues management. The record identifies a coronary stent without a documented complication.

Coding direction: I25.10 describes the CAD. Z95.5 may also be reportable for the implant status.

Reasoning: The stent does not turn the native artery into a bypass graft. Don’t assign graft atherosclerosis or a device complication based solely on the implant’s presence.

Review any other part of the record that diagnoses angina before finalizing the disease code. This example assumes there is no contradictory angina diagnosis.

Scenario 2: CAD and stable angina documented separately

The assessment lists atherosclerotic disease of the native coronary arteries and stable angina. Nothing indicates that the angina has an unrelated cause.

Coding direction: I25.118 captures the documented combination. Don’t add a separate I20 code for the same angina.

Reasoning: The coding convention supplies the presumed relationship between the established diagnoses. A query solely to obtain the words “due to CAD” is not ordinarily needed when that convention applies.

The coding decision would change if the provider documented another cause for the angina.

Scenario 3: Diseased vein graft with unstable angina

A patient with CABG has a documented atherosclerotic lesion in an autologous vein coronary bypass graft. The final assessment identifies unstable angina associated with that disease.

Coding direction: I25.710 matches the documented graft type and angina.

Reasoning: I25.700 would omit the known graft type, while I25.810 would conflict with the documented angina. Add native-coronary disease only when it is independently documented and reportable.

Review CABG status and other diagnoses under the full encounter’s instructions rather than adding them automatically from a preset bundle.

Common CAD coding errors and better checks

A useful internal audit records the reason for each correction as well as the replacement code. “Angina subtype omitted from assessment review” identifies a training issue. A spreadsheet that shows only a change from I25.10 to I25.118 does not explain what went wrong.

Don’t mark every unspecified code as an error. Sometimes it accurately reflects the available documentation. The audit should determine whether relevant detail was overlooked, rather than demanding unsupported specificity.

Claim accuracy, medical necessity and risk adjustment

A valid coronary artery disease ICD-10 code does not guarantee payment. Diagnosis coding, coverage and procedure reporting address different questions.

CMS coverage materials link cardiac procedures to specific indications and documentation requirements. Finding a CAD diagnosis on a coverage list does not remove the need to satisfy the rest of the applicable policy.

When reviewing a claim, confirm that the diagnosis pointer matches the service being billed. Don’t link an unrelated problem-list diagnosis to a cardiac procedure simply because the software accepts it.

CPT and HCPCS selection depends on the services performed. I25.10 does not dictate a particular catheterization, intervention or office-visit level. Review procedure reporting independently instead of relying on a fixed “CAD equals this CPT” pairing.

Risk adjustment also requires separate review. Check the applicable model and mapping rather than assigning a universal payment value to CAD. A diagnosis may be reportable without generating a payment adjustment. A model’s financial treatment never authorizes a diagnosis unsupported by the record.

When reviewing a denial, start with the stated reason. The problem may involve authorization, coverage, procedure coding or documentation rather than the CAD code itself.

A brief note for patients reading their records

I25.10 is a diagnosis code for billing purposes. It doesn’t indicate the severity of a blockage in the arteries. It doesn’t tell you whether you should be worried about your symptoms or what treatment you may need. If this billing code doesn’t align with what your healthcare provider told you, ask your healthcare provider for more information. You can also reach out to the billing office to find out what documented assessment led to that billing code being assigned. The Medical Billing Services team can not replace your medical provider and can not tell you what the documented assessment was. They can tell you how the assessment was reported. Call 911 if you feel you are having a heart attack. Seek emergency medical care if you have new or worsening chest pain, especially if you are experiencing shortness of breath, diaphoresis (sweating), or pain spreading to your arm or jaw.

Put the documented diagnosis first

Use I25.10 when it fits the record. Review angina, native-versus-graft involvement and applicable instructions before finalizing the code.

For your next CAD claim review, compare the provider’s assessment with the selected code and its Tabular notes. If your team needs support, request a cardiology coding review focused on documentation and code selection.

Frequently asked questions

Which ICD-10-CM code applies to CAD without angina?

I25.10 identifies atherosclerotic heart disease of the native coronary artery without angina pectoris. Confirm that the record doesn’t instead describe bypass-graft or transplanted-heart disease. A previous stent or CABG procedure alone does not establish which vessel has the disease being coded.

What is the difference between I25.10 and I25.119?

I25.10 describes native-coronary atherosclerosis without angina. I25.119 describes native-coronary atherosclerosis with angina whose type is unspecified. The distinction depends on the documented diagnosis, not simply on whether chest pain occurred during the visit. Use a more specific combination code when the angina subtype is established.

Can CAD and angina be coded separately?

Use the appropriate combination code when atherosclerotic CAD and angina are documented and the presumed relationship applies. Don’t add an I20 code for the same angina. If the provider identifies another cause, review the separate diagnoses, exclusion notes and applicable instructions before selecting the codes.

Which code applies to CAD with stable angina?

I25.118 generally applies to native-coronary atherosclerosis with stable angina. It represents other forms of angina rather than unspecified angina. Confirm the affected vessels because bypass-graft disease follows a different coding pathway. The phrase “stable CAD” alone does not establish an angina diagnosis or support this combination.

Does a history of CABG indicate graft disease?

No. CABG status and graft atherosclerosis are separate findings. Z95.1 identifies the presence of an aortocoronary bypass graft. An active graft-disease code requires documentation of disease within the graft. The patient’s native coronary arteries may remain diseased even when the bypass grafts are patent.

What is the history of CAD ICD-10 code?

There isn’t one history code that automatically replaces CAD. Z86.79 may apply to an appropriately documented resolved circulatory condition, but not to active coronary disease. Review the assessment when “history of CAD” is ambiguous. Old myocardial infarction has a separate code, I25.2, when applicable.

Will a coronary stent change the CAD diagnosis code?

Not automatically. A stent may be present in a native coronary artery, and the CAD code still depends on the diagnosed disease and angina status. Z95.5 may report implant status. A stent complication requires supporting documentation and cannot be inferred solely from the implant’s presence.

Does I25.82 need to accompany another CAD code?

I25.82 carries a code-first instruction for coronary atherosclerosis. When reporting documented chronic total coronary occlusion within that pathway, sequence the appropriate atherosclerosis code first. Use I25.82 as an additional code, not a replacement for the underlying CAD code, and distinguish chronic occlusion from an acute coronary event.

References

• CDC: ICD-10-CM overview and coding browser
• CMS: ICD-10 resources and official coding guidelines
• American Heart Association: Coronary artery disease