I25.10: Atherosclerotic heart disease of native coronary artery without angina pectoris

The ICD-10-CM code for coronary artery disease when atherosclerosis of the native coronary arteries is documented and no concurrent angina pectoris is present at the time of coding.

Billable

FY2027

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At a glance

Code Family

I25.1: Atherosclerotic heart disease of native coronary artery, within the I20–I25 ischemic heart disease block.

DRG Grouping

As the principal inpatient diagnosis, I25.10 groups to MS-DRG 302 or 303, Atherosclerosis with MCC or without MCC, in MDC 05 under the FY2027 MS-DRG v44 grouper. I25.10 is sequenced as the principal or primary diagnosis when coronary artery disease without angina is the reason for the encounter. When a patient is admitted for an acute coronary event, the acute event is coded first and I25.10 reported as a secondary code for the underlying chronic atherosclerosis.

HCC Mapping (v28)

None: I25.10 does not map to any CMS-HCC v28 category. I25.110, with unstable angina, maps to HCC 229.

Condition

Coronary artery disease

Family Specificity

The I25.1x subcategory separates coronary artery disease by angina status, and the I25.7x series covers atherosclerosis of bypass graft material rather than native vessels.

Which coronary artery disease code do I assign?

Two documented facts decide the code: whether angina is present, and whether the atherosclerosis sits in a native coronary artery or in bypass graft material. Angina type also affects risk adjustment. In the CMS-HCC v28 crosswalk, I25.110, with unstable angina, maps to HCC 229, while I25.10 and I25.119 do not map to an HCC.

When documentation says…

Code

Native-vessel coronary artery disease with unstable angina

I25.110

Assign when the record supports unstable angina alongside native-vessel atherosclerosis. This code maps to CMS-HCC v28 HCC 229, Unstable Angina and Other Acute Ischemic Heart Disease.

Atherosclerosis of a coronary artery bypass graft

I25.7-

Assign an I25.7- code when the atherosclerosis involves graft material and angina is documented. Without angina, the Index sends bypass graft atherosclerosis to I25.810. The I25.1 Excludes2 note lists atherosclerosis of coronary artery bypass graft(s) and transplanted heart (the I25.7- codes).

Known coronary artery disease, no angina documented

I25.10

Assign when the record documents atherosclerosis of native coronary arteries without concurrent or recent unstable angina. The inclusion term Atherosclerotic heart disease NOS makes this the default code when a provider documents coronary artery disease or atherosclerotic heart disease without angina. Ischemic heart disease without further detail goes to I25.9 in the Index.

Native-vessel coronary artery disease with angina, type not specified

I25.119

The residual code when angina is documented but its type is not. Angina in the record moves the encounter out of I25.10. The type should be pursued in documentation rather than left unspecified.

Tabular notes

EXCLUDES2

Subcategory I25.1 carries Excludes2 notes for atheroembolism (I75.-) and for atherosclerosis of coronary artery bypass graft(s) and transplanted heart (the I25.7- codes). Category I25 adds an Excludes2 note for non-ischemic myocardial injury (I5A). Each excluded condition may be reported with I25.10 when both are documented. For graft atherosclerosis with angina, use an I25.7- code. Without angina, the Index sends bypass graft atherosclerosis to I25.810.

USE ADDITIONAL

Subcategory I25.1 instructs: use additional code, if applicable, to identify coronary atherosclerosis due to calcified coronary lesion (I25.84) or coronary atherosclerosis due to lipid rich plaque (I25.83). Category I25 adds a Use additional code note for chronic total occlusion of coronary artery (I25.82) and for tobacco exposure, history, dependence or use (Z77.22, Z87.891, Z57.31, F17.-, Z72.0).

INCLUSION TERM

Atherosclerotic heart disease NOS. Subcategory I25.1 adds the inclusion terms atherosclerotic cardiovascular disease, coronary (artery) atheroma, coronary (artery) atherosclerosis, coronary (artery) disease and coronary (artery) sclerosis. I25.10 is the default code when a provider documents coronary artery disease or atherosclerotic heart disease without angina. Ischemic heart disease without further detail goes to I25.9 in the Index. When angina is present and documented, the appropriate I25.11x code is used instead.

FY2027 CHANGES

The FY2027 codes addenda make no addition, deletion or revision in category I25. The FY2027 tabular addenda make no change to the I20-I25 block, I25, I25.1 or I25.10 instructional notes. I25.10 is unchanged in the FY2027 update.

Operational & financial impact

Why specificity matters beyond the chart: risk adjustment, DRG assignment and denial exposure all follow from which code is selected.

CMS-HCC v28 (PY2024+)

No HCC mapping applies. I25.10 does not map to any Hierarchical Condition Category in CMS-HCC Model Version 28. Atherosclerotic coronary artery disease without angina does not carry HCC risk adjustment weight under the current model.

Where the risk adjustment sits instead

When the clinical record supports unstable angina, I25.110 is assigned instead and maps to HCC 229, Unstable Angina and Other Acute Ischemic Heart Disease, under CMS-HCC v28. Angina without a documented type is coded I25.119, which does not map to an HCC in the v28 crosswalk. Documentation of the angina type determines whether the encounter captures HCC 229.

Sequencing, outpatient and inpatient

Outpatient, code I25.10 when coronary artery disease without angina is confirmed and addressed at the encounter, sequencing it as the principal or primary diagnosis when it is the reason for the visit. When coronary artery disease is incidental to another cardiovascular condition being primarily managed, sequence according to the reason for the encounter. Inpatient, if the patient is admitted for an acute myocardial infarction, Guideline I.C.9.b sequences the I21 code first, with I25.10 reported as a secondary code for the underlying chronic atherosclerosis.

Medicare and commercial payers

There is no National Coverage Determination specific to I25.10.

Documentation checklist to support I25.10

Chart elements that support code selection and reduce specificity-driven denials.

Provider documentation of coronary artery disease or atherosclerotic heart disease of the native coronary arteries.

No documentation of concurrent angina pectoris at the encounter, since documented angina moves the code to the I25.11x series.

Specification that the vessels involved are native coronary arteries rather than bypass grafts, which belong to the I25.7x series.

Angina status and type restated at each encounter, because they determine code selection. Of I25.10, I25.110 and I25.119, only I25.110, with unstable angina, maps to an HCC under CMS-HCC v28.

A calcified coronary lesion or lipid rich plaque documented where present, which supports adding I25.84 or I25.83.

FAQ

When does coronary artery disease move off I25.10 to a with-angina code?

The code moves off I25.10 as soon as angina is documented. Unstable angina with native-vessel atherosclerosis is coded I25.110, which maps to HCC 229, Unstable Angina and Other Acute Ischemic Heart Disease, under CMS-HCC v28. Angina documented without a specified type is coded I25.119. When angina is documented, I25.10 omits it.

Does I25.10 carry any risk adjustment weight?

No. I25.10 does not map to any Hierarchical Condition Category in CMS-HCC v28. Atherosclerotic coronary artery disease without angina carries no HCC weight. In the v28 crosswalk, I25.110, with unstable angina, maps to HCC 229, while I25.119, with unspecified angina, does not.

The provider documented only coronary artery disease with no further detail. Which code applies?

Code I25.10 applies. The Index sends coronary artery disease to Disease, heart, ischemic, atherosclerotic, which is I25.10. Its inclusion term, Atherosclerotic heart disease NOS, supports the same default. Ischemic heart disease without further detail is a different Index entry and goes to I25.9.

What if the atherosclerosis involves a bypass graft rather than a native vessel?

Use a graft code, not I25.10. With angina, assign an I25.7- code. Without angina, the Index sends bypass graft atherosclerosis to I25.810. Subcategory I25.1 carries an Excludes2 note for atherosclerosis of coronary artery bypass graft(s) and transplanted heart (the I25.7- codes). I25.10 and a graft code may both be reported when native vessel and graft atherosclerosis are both documented.

Can I25.10 be reported with an acute myocardial infarction code?

Yes, I25.10 can be reported as a secondary code. When a patient with coronary artery disease is admitted due to an acute myocardial infarction, Guideline I.C.9.b sequences the I21 code before the coronary artery disease. I25.10 is then reported as a secondary code for the underlying chronic atherosclerosis.

Should I25.83 or I25.84 be added to the claim?

Yes, they are added when the documentation supports them. Coronary atherosclerosis due to lipid rich plaque (I25.83) and due to calcified coronary lesion (I25.84) are Use additional codes, if applicable, under subcategory I25.1. Add them when a calcified lesion or lipid rich plaque is documented.

Related codes

Codes in the same family as I25.10. Only codes with a published page render as links.

Sibling codes in the I25 family

I25.10: Atherosclerotic heart disease of native coronary artery without angina pectoris.
I25.110: Atherosclerotic heart disease of native coronary artery with unstable angina pectoris.
I25.119: Atherosclerotic heart disease of native coronary artery with unspecified angina pectoris.
I25.2: Old myocardial infarction.
I25.5: Ischemic cardiomyopathy.
I25.6: Silent myocardial ischemia.
I25.7-: Atherosclerosis of coronary artery bypass graft(s) and coronary artery of transplanted heart with angina pectoris.

Additional codes to consider

Codes outside the I25.1 family considered alongside I25.10.

Companion: code alongside when documented

I25.84: Coronary atherosclerosis due to calcified coronary lesion. A Use additional code, if applicable, under the I25.1 note.
I25.83: Coronary atherosclerosis due to lipid rich plaque. A Use additional code, if applicable, under the I25.1 note.

Consider instead

I25.110: Atherosclerotic heart disease of native coronary artery with unstable angina pectoris. Assign when unstable angina is documented. It maps to HCC 229 under CMS-HCC v28.
I25.119: Atherosclerotic heart disease of native coronary artery with unspecified angina pectoris. Assign when angina is documented but the type is not specified.
I25.7-: Atherosclerosis of coronary artery bypass graft(s) and coronary artery of transplanted heart with angina pectoris. Assign when graft atherosclerosis is documented with angina. Without angina, the Index sends bypass graft atherosclerosis to I25.810.
I21.9: Acute myocardial infarction, unspecified. Assign for an acute myocardial infarction of unspecified type. Type 1 STEMI takes a code from subcategories I21.0-I21.2 or code I21.3, and type 1 NSTEMI takes I21.4.
I24.9: Acute ischemic heart disease, unspecified. The Index sends acute coronary syndrome NEC to I24.9.
I25.6: Silent myocardial ischemia. Assign when silent myocardial ischemia is documented.
I20.0: Unstable angina. Assign when unstable angina is documented without atherosclerotic heart disease. When both are documented, I25.110 is used instead.

Sources

All claims on this page derive from government and professional-standards sources.

National Center for Health Statistics. (2026). International classification of diseases, tenth revision, clinical modification (ICD-10-CM) FY2027 files. https://www.cdc.gov/nchs/icd/icd-10-cm/files.html
Centers for Medicare & Medicaid Services and National Center for Health Statistics. (2026). ICD-10-CM official guidelines for coding and reporting FY2027. https://ftp.cdc.gov/pub/Health_Statistics/NCHS/Publications/ICD10CM/2027/ICD-10-CM-October-1-2026-FY27-Guidelines.pdf
Centers for Medicare & Medicaid Services. (2025). 2026 model software/ICD-10 mappings. https://www.cms.gov/medicare/payment/medicare-advantage-rates-statistics/risk-adjustment/2026-model-software-icd-10-mappings
Centers for Medicare & Medicaid Services. (2026). MS-DRG classifications and software, version 44. https://www.cms.gov/medicare/payment/prospective-payment-systems/acute-inpatient-pps/ms-drg-classifications-and-software