ICD-10-CM 2026 · Effective October 1, 2025

ICD-10 N04.20

Billable / Specific CC

Nephrotic syndrome with diffuse membranous glomerulonephritis, unspecified

N04
Block
1
Synonyms
6
LCDs
4
Payer Policies
0
Linked CPTs

About ICD-10-CM N04.20

ICD-10-CM code N04.20 represents Nephrotic syndrome with diffuse membranous glomerulonephritis, unspecified. This is a billable/specific code in the Genitourinary System chapter (block N04). The 2026 edition of ICD-10-CM N04.20 became effective on October 1, 2025.

Coding Tips for N04.20

Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.

Inpatient DRG impact: CC

N04.20 is designated CC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-CC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag CC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.

Inclusion Terms / Approximate Synonyms

Clinical terms and conditions classified under N04.20. Per CMS ICD-10-CM Tabular 2026.

  • Membranous nephropathy NOS with nephrotic syndrome

Medicare Advantage HCC Impact

ESRD-HCC
Category 141

Capture this diagnosis annually for accurate risk adjustment. Missed HCC captures are the #1 revenue leak in Medicare Advantage risk programs.

Inpatient DRG Impact, CC

codes Nephrotic syndrome with diffuse membranous glomerulonephritis, unspecified. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.

Medicare LCD Coverage for N04.20

Local Coverage Determinations (LCDs) from CMS MACs that list N04.20 as a covered diagnosis.

6 LCDs

Showing top 6. Click a CPT for full coverage scope.

CMS LCD: Billing and Coding: Magnesium
Article ID: 59186, Effective: 2025-10-01 00:00:00, 4358 covered, 0 non-covered
CPT 83735 →
CMS LCD: Billing and Coding: Mass Spectrometry (MS) Testing in Monoclonal Gammopathy (MG)
Article ID: 58921, Effective: 2024-12-15 00:00:00, 82 covered, 0 non-covered
CPT 0077U →
CMS LCD: Billing and Coding: Retroperitoneal Ultrasound
Article ID: 55336, Effective: 2025-10-01 00:00:00, 797 covered, 0 non-covered
CPT 76775 →
CMS LCD: Billing and Coding: Retroperitoneal Ultrasound
Article ID: 55336, Effective: 2025-10-01 00:00:00, 797 covered, 0 non-covered
CPT 76770 →
CMS LCD: Billing and Coding: Retroperitoneal Ultrasound
Article ID: 55336, Effective: 2025-10-01 00:00:00, 797 covered, 0 non-covered
CPT 76776 →
CMS LCD: Billing and Coding: Serum Magnesium
Article ID: 57189, Effective: 2025-10-16 00:00:00, 1405 covered, 0 non-covered
CPT 83735 →

Commercial Payer Coverage

Coverage policies from major commercial payers referencing N04.20.

4 policies

4 Medicare

Billing and Coding: Retroperitoneal Ultrasound
Policy ID: ART-55336
Billing and Coding: Serum Magnesium
Policy ID: ART-57189
Billing and Coding: Mass Spectrometry (MS) Testing in Monoclonal Gammopathy (MG)
Policy ID: ART-58921
Billing and Coding: Magnesium
Policy ID: ART-59186

CPT Codes Commonly Billed with N04.20

Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.

No procedure linkages on file for N04.20

We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.

Codes Adjacent To N04.20

Other codes in section N00-N08 (Glomerular diseases).

N00 Acute nephritic syndrome (non-billable) N00.0 Acute nephritic syndrome with minor glomerular abnormality N00.1 Acute nephritic syndrome with focal and segmental glomerular lesions N00.2 Acute nephritic syndrome with diffuse membranous glomerulonephritis N00.3 Acute nephritic syndrome with diffuse mesangial proliferative glomerulonephritis N00.4 Acute nephritic syndrome with diffuse endocapillary proliferative glomerulonephritis N00.5 Acute nephritic syndrome with diffuse mesangiocapillary glomerulonephritis N00.6 Acute nephritic syndrome with dense deposit disease N00.7 Acute nephritic syndrome with diffuse crescentic glomerulonephritis N00.8 Acute nephritic syndrome with other morphologic changes N00.9 Acute nephritic syndrome with unspecified morphologic changes N00.A Acute nephritic syndrome with C3 glomerulonephritis N00.B Acute nephritic syndrome with immune complex membranoproliferative glomerulonephritis (non-billable) N00.B1 Acute nephritic syndrome with idiopathic immune membranoproliferative glomerulonephritis (IC-MPGN) N00.B2 Acute nephritic syndrome with secondary immune complex membranoproliferative glomerulonephritis (IC-MPGN) N01 Rapidly progressive nephritic syndrome (non-billable) N01.0 Rapidly progressive nephritic syndrome with minor glomerular abnormality N01.1 Rapidly progressive nephritic syndrome with focal and segmental glomerular lesions N01.2 Rapidly progressive nephritic syndrome with diffuse membranous glomerulonephritis N01.3 Rapidly progressive nephritic syndrome with diffuse mesangial proliferative glomerulonephritis

ICD-10 N04.20, Billing FAQ

Is ICD-10 code N04.20 billable? +

Yes, N04.20 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.

What other names or terms map to N04.20? +

ICD-10 N04.20 includes: Membranous nephropathy NOS with nephrotic syndrome.

Is N04.20 a CC or MCC for inpatient DRG? +

Yes, this code is designated as CC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.

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Reviewed by the PayerReady Medical Coding Team

Verified against the CMS 2026 code set on May 31, 2026.

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