R79
Non-Billable (Header)Other abnormal findings of blood chemistry
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
What This Code Means
R79 is the ICD-10-CM diagnosis code for other abnormal findings of blood chemistry. R79 sits in the ICD-10-CM chapter for symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (r00-r99), within the section covering abnormal findings on examination of blood, without diagnosis (r70-r79).
Header codes like R79 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 R79'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 R79 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Excludes 1 — Do NOT code together
- asymptomatic hyperuricemia (E79.0)
- hyperglycemia NOS (R73.9)
- hypoglycemia NOS (E16.2)
- neonatal hypoglycemia (P70.3-P70.4)
- specific findings indicating disorder of amino-acid metabolism (E70-E72)
- specific findings indicating disorder of carbohydrate metabolism (E73-E74)
- specific findings indicating disorder of lipid metabolism (E75.-)
Use Additional Code
- code to identify any retained foreign body, if applicable (Z18.-)