N03.A ICD-10-CM Code: Chronic nephritic syndrome with C3 glomerulonephritis
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Diseases of the genitourinary system (N00-N99) / Glomerular diseases (N00-N08)
N03.A
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceChronic nephritic syndrome with C3 glomerulonephritis
A chronic kidney disease caused by abnormal deposits of a protein called C3 in the kidney's filtering structures, leading to inflammation and damage.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
N/A—
Not mapped
ACA/HHS
N/A—
Not mapped
ESRD/PACE
N/A—
Not mapped
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
Official- Chronic nephritic syndrome with C3 glomerulopathy
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for N03.A in this effective period.
Related Child Codes
Includes
Official- chronic glomerular disease
- chronic glomerulonephritis
- chronic nephritis
Excludes 1
Official- Chronic nephritic syndrome (with C3 glomerulopathy) with dense deposit disease (N03.6)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for N03.A in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for N03.A in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for N03.A in this effective period.
Buddy Documentation Tip
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is N03.A an HCC code?
No. N03.A is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
- Code
- N03.A
- Description
- Chronic nephritic syndrome with C3 glomerulonephritis
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF
- —
- Billable
- Yes
- Payment year
- 2026
Coder workflow notes
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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
N03.A is the ICD-10-CM diagnosis code for chronic nephritic syndrome with c3 glomerulonephritis. A chronic kidney disease caused by abnormal deposits of a protein called C3 in the kidney's filtering structures, leading to inflammation and damage. N03.A sits in the ICD-10-CM chapter for diseases of the genitourinary system (n00-n99), within the section covering glomerular diseases (n00-n08).
N03.A is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
C3 glomerulonephritis is confirmed through immunofluorescence microscopy showing C3 dominant staining.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for N03.A sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •C3 glomerulonephritis is confirmed through immunofluorescence microscopy showing C3 dominant staining
- •This is a relatively newer recognized disease entity, so ensure documentation explicitly mentions C3 glomerulonephritis
Excludes 1, Do NOT code together
- Chronic nephritic syndrome (with C3 glomerulopathy) with dense deposit disease (N03.6)