N04.B1: Nephrotic syndrome with idiopathic immune complex membranoproliferative glomerulonephritis (IC-MPGN)

New code · FY2026

Billable: use this code on claims.

• New code, effective October 1, 2025 (FY2026).

Code breakdown

Coding notes

Includes (from N04)

• congenital nephrotic syndrome
• lipoid nephrosis

Medicare coverage

N04.B1 is listed as a covered diagnosis in 2 Medicare billing and coding articles:

• A54548 Billing and Coding: Eculizumab, and Biosimilars: EPYSQLI®-eculizumab-aagh, and BKEMV™-eculizumab-aeeb
• A59186 Billing and Coding: Magnesium

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All FY2026 ICD-10-CM changes

ICD-10-CM codes and descriptions are from the CMS and NCHS code files. Coverage is from the CMS Medicare Coverage Database billing and coding articles.