N06.21
BillablePrimary membranous nephropathy with isolated proteinuria
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is N06.21 an HCC code?
No. N06.21 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
N06.21 is the ICD-10-CM diagnosis code for primary membranous nephropathy with isolated proteinuria. A condition where protein is found in the urine caused by primary membranous nephropathy, an autoimmune disease where the kidney's filtering membrane is damaged without an underlying secondary cause. N06.21 sits in the ICD-10-CM chapter for diseases of the genitourinary system (n00-n99), within the section covering glomerular diseases (n00-n08).
N06.21 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Primary membranous nephropathy is often associated with PLA2R or THSD7A antibodies; document serology results when available.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for N06.21 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Primary membranous nephropathy is often associated with PLA2R or THSD7A antibodies; document serology results when available
- •Distinguish from secondary membranous nephropathy (associated with lupus, infections, malignancy) which would require additional coding
Excludes 1 — Do NOT code together
- primary membranous nephropathy with nephrotic syndrome (N04.21)