2026 ICD-10-CM Diagnosis Code N00.B1Acute nephritic syndrome with idiopathic immune membranoproliferative glomerulonephritis (IC-MPGN)

ICD-10-CM Codes›N00–N99›N00-N08›N00

ICD-10-CM N00.B1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N00.B1 is a billable ICD-10-CM diagnosis code for acute nephritic syndrome with idiopathic immune 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
N00.B1
Billable Status
Yes — Valid for Submission
Code Describes
Acute nephritic syndrome with idiopathic immune membranoproliferative glomerulonephritis (IC-MPGN)
Short Description
Ac neph synd with idio imm membr prolif glomrlneph (IC-MPGN)
Parent Code
N00.B
Acute nephritic syndrome with immune complex membranoproliferative glomerulonephritis

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN00-N08Glomerular diseases
CategoryN00Acute nephritic syndrome
This CodeN00.B1Acute nephritic syndrome with idiopathic immune 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)
      • acute
        • with
          • idiopathic immune membranoproliferative glomerulonephritis (IC-MPGN)

Code History & ChangesHistory

New Code N00.B1 was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.

Replacement N00.B1 replaces the following previously assigned code(s):

  • N00.8 - Acute nephritic 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 N00.B1Overview

Is N00.B1 a billable code?

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

What MS-DRG does N00.B1 group to?

When acute nephritic syndrome with idiopathic immune 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.