Skip to content

N05.5

Billable

Unspecified nephritic syndrome with diffuse mesangiocapillary glomerulonephritis

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

Is N05.5 an HCC code?

No. N05.5 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

N05.5 is the ICD-10-CM diagnosis code for unspecified nephritic syndrome with diffuse mesangiocapillary glomerulonephritis. A kidney disease characterized by inflammation and protein in the urine, with a specific type of glomerular damage called diffuse mesangiocapillary glomerulonephritis affecting the filtering units of the kidneys. N05.5 sits in the ICD-10-CM chapter for diseases of the genitourinary system (n00-n99), within the section covering glomerular diseases (n00-n08).

N05.5 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.

This code specifies the morphologic pattern of glomerulonephritis; ensure pathology reports confirm mesangiocapillary changes before coding.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for N05.5 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • This code specifies the morphologic pattern of glomerulonephritis; ensure pathology reports confirm mesangiocapillary changes before coding
  • N05.5 is used when the nephritic syndrome is unspecified but the glomerular pathology is identified as mesangiocapillary

Excludes 1 — Do NOT code together

  • Unspecified nephritic syndrome with C3 glomerulonephritis (N05.A)
  • Unspecified nephritic syndrome with C3 glomerulopathy (N05.A)

Code Hierarchy

N05Unspecified nephritic syndromeN05.5Unspecified nephritic syndrome with diffuse mesangiocapillary glomerulonephritis
N05.5Unspecified nephritic syndrome with diffuse mesangiocapillary glomerulonephritis

Open N05.5 in the Interactive Encoder

See full code details, AI coding tips, HCC mappings, and related codes in our interactive encoder. Start your 14-day Pro trial — no credit card required.