ICD-10-CM 2027
ICD-10 code for subacute nephritis
Rapidly progressive nephritic syndrome with unspecified morphologic changes
From the official ICD-10-CM alphabetic index entry “Nephritis, nephritic (albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic) › subacute”. Page updated September 29, 2026.
About coding subacute nephritis
The ICD-10-CM code for subacute nephritis is N01.9 (Rapidly progressive nephritic syndrome with unspecified morphologic changes).
Within N01, choose N01.9 (with unspecified morphologic changes) only when documentation doesn't support a more specific option: with minor glomerular abnormality (N01.0), with focal and segmental glomerular lesions (N01.1), with diffuse membranous glomerulonephritis (N01.2), with diffuse mesangial proliferative glomerulonephritis (N01.3), with diffuse endocapillary proliferative glomerulonephritis (N01.4), with diffuse mesangiocapillary glomerulonephritis (N01.5), with dense deposit disease (N01.6), with diffuse crescentic glomerulonephritis (N01.7) and 2 more.
As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 698 (Other Kidney and Urinary Tract Diagnoses with MCC, relative weight 1.6398), DRG 699 (Other Kidney and Urinary Tract Diagnoses with CC, relative weight 1.0003), DRG 700 (Other Kidney and Urinary Tract Diagnoses without CC/MCC, relative weight 0.6741), DRG 791 (Prematurity with Major Problems, relative weight 4.1075) and DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), in MDC 11 (Diseases and Disorders of the Kidney and Urinary Tract) and MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about subacute nephritis ICD-10 codes
What is the ICD-10 code for subacute nephritis?
- N01.9 — Rapidly progressive nephritic syndrome with unspecified morphologic changes.
Is N01.9 billable?
- Yes. N01.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can N01.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict N01.9 as a principal diagnosis.
Is N01.9 a CC or MCC?
- N01.9 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.