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E79

Non-Billable (Header)

Disorders of purine and pyrimidine metabolism

Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)

What This Code Means

E79 is the ICD-10-CM diagnosis code for disorders of purine and pyrimidine metabolism. E79 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).

Header codes like E79 cannot be reported on claims directly — they organize child codes that share clinical context but the actual diagnosis must be coded to the highest level of specificity supported by the documentation. Coders should look at E79's child codes and select the one that matches the patient's documented presentation, since payers reject header codes submitted as the primary diagnosis. For risk adjustment workflows, header codes never contribute to a Medicare Advantage member's RAF score on their own; only billable child codes that happen to map to a payment HCC affect risk-adjusted plan payments.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E79 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Excludes 1 — Do NOT code together

  • 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)

Child Codes

Code Hierarchy

E79Disorders of purine and pyrimidine metabolism
E79Disorders of purine and pyrimidine metabolism

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