2026 ICD-10-CM Diagnosis Code N00.5Acute nephritic syndrome with diffuse mesangiocapillary glomerulonephritis

ICD-10-CM Codes›N00–N99›N00-N08›N00

ICD-10-CM N00.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N00.5 is a billable ICD-10-CM diagnosis code for acute nephritic syndrome with diffuse mesangiocapillary glomerulonephritis. 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. Coders also document this condition as acute nephritic syndrome co-occurrent and due to membranoproliferative glomerulonephritis type III. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nephritis; nephrosis; renal sclerosis.

Code Identity

ICD-10-CM Code
N00.5
Billable Status
Yes — Valid for Submission
Code Describes
Acute nephritic syndrome with diffuse mesangiocapillary glomerulonephritis
Short Description
Acute nephritic syndrome w diffuse mesangiocap glomrlneph
Parent Code
N00
Acute nephritic syndrome

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN00-N08Glomerular diseases
CategoryN00Acute nephritic syndrome
This CodeN00.5Acute nephritic syndrome with diffuse mesangiocapillary glomerulonephritis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute nephritic syndrome co-occurrent and due to membranoproliferative glomerulonephritis type III
  • Acute nephritic syndrome, diffuse mesangiocapillary glomerulonephritis
  • Mesangiocapillary glomerulonephritis type III

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 1 Excludes

  • Acute nephritic syndrome with C3 glomerulonephritis N00.A
  • Acute nephritic syndrome with C3 glomerulopathy N00.A

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
          • diffuse
            • mesangiocapillary glomerulonephritis

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR GEN001
Nephritis; nephrosis; renal sclerosis
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Kidney Diseases

You have two kidneys, each about the size of your fist. They are near the middle of your back, just below the rib cage. Inside each kidney there are about a million tiny structures called nephrons. They filter your blood. They remove wastes and extra water, which become urine. The urine flows through tubes called ureters.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert N00.5 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
580.0 Ac proliferat nephritis
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About N00.5Overview

Is N00.5 (Acute nephritic syndrome) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report acute nephritic syndrome with diffuse mesangiocapillary glomerulonephritis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does N00.5 group to?

When acute nephritic syndrome with diffuse mesangiocapillary glomerulonephritis 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.

What is the ICD-9 equivalent of N00.5?

Under the General Equivalence Mappings, acute nephritic syndrome with diffuse mesangiocapillary glomerulonephritis converts to ICD-9-CM 580.0 (ac proliferat nephritis). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.