N01.9
Rapidly progressive nephritic syndrome with unspecified morphologic changes
N01.9 (also written N019) is a billable ICD-10-CM diagnosis code for rapidly progressive nephritic syndrome with unspecified morphologic changes. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 11 codes in category N01 (Rapidly progressive nephritic syndrome). The Alphabetic Index lists it under 10 entries. Its coding notes include a Code also instruction, 2 Excludes1 entries and 8 Excludes2 entries.
Code also
Two codes may be needed to describe the condition. This note gives no sequencing order.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (8 notes)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Hospital MCC
Counts as a major complication or comorbidity (MCC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 286 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.
Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix CIncludes
Further defines or gives examples of the content of the category.
- rapidly progressive glomerular disease
- rapidly progressive glomerulonephritis
- rapidly progressive nephritis
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 10 entries
- Disease, diseased, glomerular, rapidly progressive
- Disease, diseased, renal (functional) (pelvis), rapidly progressive
- Disease, diseased, renal (functional) (pelvis), subacute
- Glomerulonephritis, poststreptococcal NEC, rapidly progressive
- Glomerulonephritis, rapidly progressive
- Glomerulonephritis, subacute
- Nephritis, nephritic (albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic), poststreptococcal, rapidly progressive
- Nephritis, nephritic (albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic), rapidly progressive
- Nephritis, nephritic (albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic), subacute
- Syndrome, nephritic, rapidly progressive