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I25.1 vs I70.344

I25.1 (Atherosclerotic heart disease of native coronary artery) compared with I70.344 (Atherosclerosis of unspecified type of bypass graft(s) of the left leg with ulceration of heel and midfoot), from the official CMS tabular data.

Summary

These codes can be reported together when both conditions are documented, because I70.344 lists I25.1 under Excludes2, which marks them as distinct conditions.

Official rule
What is different?

The conditions named and billing status.I25.1 is “Atherosclerotic heart disease of native coronary artery”; I70.344 is “Atherosclerosis of unspecified type of bypass graft(s) of the left leg with ulceration of heel and midfoot”. I25.1 is a non-billable header; I70.344 is billable.

Registry fact

Can these codes be reported together?

Yes, when both are documented.I70.344 lists I25.1 under Excludes2: “arteriosclerotic cardiovascular disease (I25.1-)”. Excludes2 marks distinct conditions that may both be reported when both are documented.

Official ruleGuide: Excludes1 vs Excludes2

Is there an Excludes1 relationship?

None.Neither entry carries an Excludes1 note that names the other code. I70.344 carries 1 Excludes1 note covering other codes; the side-by-side table quotes them.

Official rule

Is there an Excludes2 relationship?

Yes.I70.344’s tabular entry: “arteriosclerotic cardiovascular disease (I25.1-)”. The note covers I25.1.

Official ruleGuide: Excludes1 vs Excludes2

Is one more specific?

Not comparable.The codes sit in different categories; specificity is only comparable within one category.

Is one a parent or header code?

One is a header.I25.1 is a non-billable header, but I70.344 is not one of its subdivisions.

Registry fact

Are there sequencing instructions?

None.Neither entry carries a Code First or Use Additional Code note that names the other.

Official rule

Are there other coding relationships?

None found.No laterality, encounter-phase, Table of Neoplasms, Table of Drugs and Chemicals, or history-versus-active-disease relationship links these codes.

MedCoder-derived

Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule. How to read the labels

Can these codes be reported together?

Informational

Excludes2 relationship

I70.344
Atherosclerosis of unspecified type of bypass graft(s) of the left leg with ulceration of heel and midfoot
↔
I25.1
Atherosclerotic heart disease of native coronary artery

What we found

Yes, when both are documented.I70.344 carries an Excludes2 note covering I25.1: “arteriosclerotic cardiovascular disease (I25.1-)”

Excludes2 marks distinct conditions — both may be reported when both are documented.

What to review

Report both only when the documentation supports both conditions; otherwise report the one documented.

Guide: Excludes1 vs Excludes2Check these on a claim

Why it matters

An Excludes2 note means the excluded condition is not part of the code above it, but a patient can have both. Report both when both are documented.

Source / rule

CMS ICD-10-CM tabular instructional notes

Official guidance behind these answers

  • Section I.A.12.b — Excludes2 · applies to: Excludes2

    A type 2 Excludes note represents “Not included here.” An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

    ICD-10-CM Official Guidelines FY2026

Quoted from the ICD-10-CM Official Guidelines for Coding and Reporting in effect for the release shown. The tabular notes above are the code-level instruction; these sections are the convention that says how such a note is applied. Source document (CMS PDF) · Release and checksum

Side by side

I25.1Atherosclerotic heart disease of native coronary arteryI70.344Atherosclerosis of unspecified type of bypass graft(s) of the left leg with ulceration of heel and midfoot
Billing statusNon-billable header

Report instead: I25.10, I25.110, I25.111, I25.112, I25.118

Billable
ClassificationI00-I99 — Diseases of the Circulatory System (I00-I99)I00-I99 — Diseases of the Circulatory System (I00-I99)
DefinitionAtherosclerotic heart disease of native coronary artery is a non-billable ICD-10-CM category code (I25.1).Atherosclerosis of unspecified type of bypass graft(s) of the left leg with ulceration of heel and midfoot is a billable ICD-10-CM diagnosis code (I70.344).
Includes
Atherosclerotic cardiovascular disease
Coronary (artery) atheroma
Coronary (artery) atherosclerosis
Coronary (artery) disease
any condition classifiable to I70.312 and I70.322
chronic limb-threatening ischemia of unspecified type of bypass graft(s) of the left leg with ulceration
critical limb ischemia of unspecified type of bypass graft(s) of the left leg with ulceration
arteriolosclerosis
Excludes1—
embolism or thrombus of bypass graft(s) of extremities (T82.8-)
Excludes2
atheroembolism (I75.-)
atherosclerosis of coronary artery bypass graft(s) and transplanted heart (I25.7-)
non-ischemic myocardial injury (I5A)
arteriosclerotic cardiovascular disease (I25.1-)
arteriosclerotic heart disease (I25.1-)
atheroembolism (I75.-)
cerebral atherosclerosis (I67.2)
coronary atherosclerosis (I25.1-)
mesenteric atherosclerosis (K55.1)
precerebral atherosclerosis (I67.2)
primary pulmonary atherosclerosis (I27.0)
Use additional code
code, if applicable, to identify:
coronary atherosclerosis due to calcified coronary lesion (I25.84)
coronary atherosclerosis due to lipid rich plaque (I25.83)
code to identify severity of ulcer (L97.-)
code, if applicable, to identify chronic total occlusion of artery of extremity (I70.92)
code to identify:
Code also
the presence of hypertension (I10-I1A)
—

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on.

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Derived from the official CMS ICD-10-CM tabular data (FY2027). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources