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N26

Non-Billable (Header)

Unspecified contracted kidney

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

What This Code Means

N26 is the ICD-10-CM diagnosis code for unspecified contracted kidney. N26 sits in the ICD-10-CM chapter for diseases of the genitourinary system (n00-n99), within the section covering other disorders of kidney and ureter (n25-n29).

Header codes like N26 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 N26'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 N26 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Excludes 1 — Do NOT code together

  • contracted kidney due to hypertension (I12.-)
  • diffuse sclerosing glomerulonephritis (N05.8.-)
  • hypertensive nephrosclerosis (arteriolar) (arteriosclerotic) (I12.-)
  • small kidney of unknown cause (N27.-)

Child Codes

Code Hierarchy

N26Unspecified contracted kidney
N26Unspecified contracted kidney

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