2026 ICD-10-CM Diagnosis Code N06.21Primary membranous nephropathy with isolated proteinuria

ICD-10-CM Codes›N00–N99›N00-N08›N06

ICD-10-CM N06.21
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N06.21 is a billable ICD-10-CM diagnosis code for primary membranous nephropathy with isolated proteinuria. 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 idiopathic glomerulonephritis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nephritis; nephrosis; renal sclerosis and Proteinuria.

Code Identity

ICD-10-CM Code
N06.21
Billable Status
Yes — Valid for Submission
Code Describes
Primary membranous nephropathy with isolated proteinuria
Short Description
Primary membranous nephropathy with isolated proteinuria
Same as the full description in the CMS dataset.
Parent Code
N06.2
Isolated proteinuria with diffuse membranous glomerulonephritis

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN00-N08Glomerular diseases
CategoryN06Isolated proteinuria with specified morphological lesion
This CodeN06.21Primary membranous nephropathy with isolated proteinuria

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Idiopathic glomerulonephritis
  • Idiopathic membranous glomerulonephritis

Tabular List NotesGuidance

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

Inclusion Terms

  • Idiopathic membranous nephropathy (with isolated proteinuria)
  • Primary membranous nephropathy, NOS

Type 1 Excludes

  • primary membranous nephropathy with nephrotic syndrome N04.21

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.

    • Nephropathy
      • membranous (diffuse)
        • primary

Clinical ClassificationClinical

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

CCSR GEN001
Nephritis; nephrosis; renal sclerosis
Default principal diagnosis: inpatient No · outpatient No
CCSR GEN010
Proteinuria
Default principal diagnosis: inpatient Yes · outpatient Yes

Code History & ChangesHistory

Replacement N06.21 replaces the following previously assigned code(s):

  • N06.2 - Isolated proteinuria w diffuse membranous glomerulonephritis
FY 2024AddedAdded to the ICD-10-CM code setEffective October 1, 2023.
FY 2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About N06.21Overview

Is N06.21 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report primary membranous nephropathy with isolated proteinuria on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does N06.21 group to?

When primary membranous nephropathy with isolated proteinuria 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.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.