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E79.9 vs Q79.6

E79.9 (Disorder of purine and pyrimidine metabolism, unspecified) compared with Q79.6 (Ehlers-Danlos syndromes), 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 can be reported together when both conditions are documented, because E79.9 lists Q79.6 under Excludes2, which marks them as distinct conditions.

Official rule
What is different?

The conditions named, billing status and chapter.E79.9 is “Disorder of purine and pyrimidine metabolism, unspecified”; Q79.6 is “Ehlers-Danlos syndromes”. Q79.6 is a non-billable header; E79.9 is billable. E79.9 sits in E00-E89 — Endocrine, Nutritional and Metabolic Diseases (E00-E89); Q79.6 in Q00-QA1 — Congenital Malformations, Deformations and Chromosomal Abnormalities (Q00-QA1).

Registry fact

Can these codes be reported together?

Yes, when both are documented.E79.9 lists Q79.6 under Excludes2: “Ehlers-Danlos syndromes (Q79.6-)”. 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. E79.9 carries 16 Excludes1 notes covering other codes; the side-by-side table quotes them.

Official rule

Is there an Excludes2 relationship?

Yes.E79.9’s tabular entry: “Ehlers-Danlos syndromes (Q79.6-)”. The note covers Q79.6.

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.Q79.6 is a non-billable header, but E79.9 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

E79.9
Disorder of purine and pyrimidine metabolism, unspecified
↔
Q79.6
Ehlers-Danlos syndromes

What we found

Yes, when both are documented.E79.9 carries an Excludes2 note covering Q79.6: “Ehlers-Danlos syndromes (Q79.6-)”

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 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
E79.9

Disorder of purine and pyrimidine metabolism, unspecified

Q79.6

Ehlers-Danlos syndromes

StatusDiffers
E79.9
Billable
Q79.6
Non-billable header

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

Report instead: Q79.60, Q79.61, Q79.62, Q79.63, Q79.69

Excludes1Differs
E79.9
  • Ataxia-telangiectasia (Q87.19)
  • Bloom's syndrome (Q82.8)
  • Cockayne's syndrome (Q87.19)
  • calculus of kidney (N20.0)
  • combined immunodeficiency disorders (D81.-)
  • Fanconi's anemia (D61.09)
  • gout (M1A.-, M10.-)
  • orotaciduric anemia (D53.0)
  • progeria (E34.8)
  • Werner's syndrome (E34.8)
  • xeroderma pigmentosum (Q82.1)
  • androgen insensitivity syndrome (E34.5-)
  • congenital adrenal hyperplasia (E25.0)
  • hemolytic anemias attributable to enzyme disorders (D55.-)
  • Marfan syndrome (Q87.4-)
  • 5-alpha-reductase deficiency (E29.1)
Q79.6

None at this code

Excludes2Differs
E79.9
  • Ehlers-Danlos syndromes (Q79.6-)
Q79.6
  • congenital (sternomastoid) torticollis (Q68.0)
CategoryDiffers
E79.9

E79 Disorders of purine and pyrimidine metabolism

Q79.6

Q79 Congenital malformations of musculoskeletal system, not elsewhere classified

ChapterDiffers
E79.9

E00-E89 — Endocrine, Nutritional and Metabolic Diseases (E00-E89)

Q79.6

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

No Code first, Use additional code, Code also, Includes 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, notes every code shares are dimmed.

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