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I67.1 vs Q28

I67.1 (Cerebral aneurysm, nonruptured) compared with Q28 (Other congenital malformations of circulatory system), from the official CMS tabular data.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Summary

These codes should not be reported together because I67.1’s tabular entry lists Q28 under Excludes1.

Official rule
What is different?

The conditions named, billing status and chapter.I67.1 is “Cerebral aneurysm, nonruptured”; Q28 is “Other congenital malformations of circulatory system”. Q28 is a non-billable header; I67.1 is billable. I67.1 sits in I00-I99 — Diseases of the Circulatory System (I00-I99); Q28 in Q00-QA1 — Congenital Malformations, Deformations and Chromosomal Abnormalities (Q00-QA1).

Registry fact

Can these codes be reported together?

No.I67.1’s entry carries an Excludes1 note covering Q28: “congenital cerebral aneurysm, nonruptured (Q28.-)”. Both may be reported only when the documentation shows the two conditions are unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Official ruleGuide: Excludes1 vs Excludes2

Is there an Excludes1 relationship?

Yes.I67.1’s tabular entry: “congenital cerebral aneurysm, nonruptured (Q28.-)”. The note covers Q28.

Official ruleGuide: Excludes1 vs Excludes2

Is one a parent or header code?

One is a header.Q28 is a non-billable header, but I67.1 is not one of its subdivisions.

Registry fact

Nothing found in 3 other checks; 1 check does not apply
Is there an Excludes2 relationship?

None.Neither entry carries an Excludes2 note that names the other code. I67.1 carries 1 Excludes2 note and Q28 carries 3 Excludes2 notes covering other codes; the side-by-side table quotes them.

Official rule

Is one more specific?

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

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?

Excludes1 — generally not reported together

Excludes1 conflict

I67.1
Cerebral aneurysm, nonruptured
↔
Q28
Other congenital malformations of circulatory system

What we found

No — do not report together.I67.1 carries an Excludes1 note covering Q28: “congenital cerebral aneurysm, nonruptured (Q28.-)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

What to review

Report one of the two. Both may be reported only when the documentation shows the two conditions are unrelated to each other.

Guide: Excludes1 vs Excludes2Check these on a claim

Why it matters

An Excludes1 note means the two conditions are not ordinarily reported together for the same encounter, because the classification treats them as mutually exclusive forms of the same condition. The documented exception is when the two conditions are unrelated to each other.

Source / rule

CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a

Official guidance behind these answers

  • Section I.A.12.a — Excludes1 · applies to: Excludes1

    A type 1 Excludes note is a pure excludes note. It means “NOT CODED HERE!” An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition. An exception to the Excludes1 definition is the circumstance when the two conditions are unrelated to each other. If it is not clear whether the two conditions involving an Excludes1 note are related or not, query the provider. For example, code F45.8, Other somatoform disorders, has an Excludes1 note for "sleep related teeth grinding (G47.63)," because "teeth grinding" is an inclusion term under F45.8. Only one of these two codes should be assigned for teeth grinding. However psychogenic dysmenorrhea is also an inclusion term under F45.8, and a patient could have both this condition and sleep related teeth grinding. In this case, the two conditions are clearly unrelated to each other, and so it would be appropriate to report F45.8 and G47.63 together.

    ICD-10-CM Official Guidelines FY2027

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

Similar descriptions do not make codes interchangeable. The documentation and the official instructions decide which code applies.

Official descriptionDiffers
I67.1

Cerebral aneurysm, nonruptured

Q28

Other congenital malformations of circulatory system

StatusDiffers
I67.1
Billable
Q28
Non-billable header

A header is not reported on a claim; a code beneath it is.

Report instead: Q28.0, Q28.1, Q28.2, Q28.3, Q28.8

Excludes1Differs
I67.1
  • congenital cerebral aneurysm, nonruptured (Q28.-)
  • ruptured cerebral aneurysm (I60.7)
  • Occlusion and stenosis of cerebral artery causing cerebral infarction (I63.3-I63.5-)
  • Occlusion and stenosis of precerebral artery causing cerebral infarction (I63.2-)
  • traumatic intracranial hemorrhage (S06.-)
Q28
  • congenital aneurysm NOS (Q27.8)
  • congenital coronary aneurysm (Q24.5)
  • ruptured cerebral arteriovenous malformation (I60.8)
  • ruptured malformation of precerebral vessels (I72.0)
Excludes2Differs
I67.1
  • sequelae of the listed conditions (I69.8)
Q28
  • congenital peripheral aneurysm (Q27.8)
  • congenital pulmonary aneurysm (Q25.79)
  • congenital retinal aneurysm (Q14.1)
Use additional codeDiffers
I67.1
  • code to identify presence of:
  • alcohol abuse and dependence (F10.-)
  • exposure to environmental tobacco smoke (Z77.22)
  • history of tobacco dependence (Z87.891)
  • hypertension (I10-I1A)
  • occupational exposure to environmental tobacco smoke (Z57.31)
  • tobacco dependence (F17.-)
  • tobacco use (Z72.0)
Q28

None at this code

CategoryDiffers
I67.1

I67 Other cerebrovascular diseases

Q28

Is itself a category

ChapterDiffers
I67.1

I00-I99 — Diseases of the Circulatory System (I00-I99)

Q28

Q00-QA1 — Congenital Malformations, Deformations and Chromosomal Abnormalities (Q00-QA1)

IncludesDiffers
I67.1
  • Cerebral aneurysm NOS
  • Cerebral arteriovenous fistula, acquired
  • Internal carotid artery aneurysm, intracranial portion
  • Internal carotid artery aneurysm, NOS
Q28

None at this code

No Code first, Code also and 7th character note at either code.

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. In a row that differs, each code’s own notes are listed under it, and the notes every code shares are listed once beneath them.

Edit this comparisonCheck a whole claim

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