2026 ICD-10-CM Diagnosis Code N04.B1Nephrotic syndrome with idiopathic immune complex membranoproliferative glomerulonephritis (IC-MPGN)

ICD-10-CM Codes›N00–N99›N00-N08›N04

ICD-10-CM N04.B1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N04.B1 is a billable ICD-10-CM diagnosis code for nephrotic syndrome with idiopathic immune complex membranoproliferative glomerulonephritis (IC-MPGN). It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 698 through 700.

Code Identity

ICD-10-CM Code
N04.B1
Billable Status
Yes — Valid for Submission
Code Describes
Nephrotic syndrome with idiopathic immune complex membranoproliferative glomerulonephritis (IC-MPGN)
Short Description
Nep syn w idio imm cmplx membr prolif glomrlneph (IC-MPGN)
Parent Code
N04.B
Nephrotic syndrome with immune complex membranoproliferative glomerulonephritis (IC-MPGN)

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN00-N08Glomerular diseases
CategoryN04Nephrotic syndrome
This CodeN04.B1Nephrotic syndrome with idiopathic immune complex membranoproliferative glomerulonephritis (IC-MPGN)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Nephritis, nephritic(albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic)
      • with
        • glomerular lesion
          • idiopathic immune membranoproliferative glomerulonephritis (IC-MPGN)

Code History & ChangesHistory

New Code N04.B1 was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.

Replacement N04.B1 replaces the following previously assigned code(s):

  • N04.8 - Nephrotic syndrome with other morphologic changes
FY 2026AddedAdded to the ICD-10-CM code setEffective October 1, 2025.
FY 2026CurrentRevised in the current code setEffective October 1, 2025 through September 30, 2026.

Questions About N04.B1Overview

Is N04.B1 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report nephrotic syndrome with idiopathic immune complex membranoproliferative glomerulonephritis (IC-MPGN) on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does N04.B1 group to?

When nephrotic syndrome with idiopathic immune complex membranoproliferative glomerulonephritis (IC-MPGN) is the principal diagnosis on an inpatient stay, it groups to MS-DRG 698, 699, 700, with relative weights from 0.6899 to 1.6544 depending on complications. Higher weights mean higher Medicare reimbursement.