2027 ICD-10-CM Diagnosis Code N05.9Unspecified nephritic syndrome with unspecified morphologic changes
ICD-10-CM Codes›N00–N99›N00-N08›N05
- Billable — Valid for Submission
- Chronic Condition
N05.9 is a billable ICD-10-CM diagnosis code for unspecified nephritic syndrome with unspecified morphologic changes. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 698 through 700. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nephritis; nephrosis; renal sclerosis.
N05.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the ESRD (V21) category 141 for payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
N05.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Anal atresia
- Bacterial nephritis
- Congenital nephritis
- Cytomegalovirus-induced glomerulonephritis
- De novo glomerulonephritis
- De novo transplant disease
- Exudative glomerulonephritis
- Exudative nephritis
- Glomerular disease
- Glomerular hematuria
- Glomerulitis
- Glomerulonephritis
- Glomerulonephritis due to vasculitis
- Idiopathic glomerular disease
- Idiopathic glomerulonephritis
- Idiopathic non-lupus full-house nephropathy
- Immunotactoid glomerulonephritis
- Lowe Kohn Cohen syndrome
- Monoclonal gammopathy of renal significance
- Monoclonal immunoglobulin-associated kidney disease
- Nephritic syndrome
- Nephritis
- Nephritis caused by ionizing radiation
- Nephrotic syndrome secondary to glomerulonephritis
- Nephrotic-nephritic syndrome
- Non-amyloid fibrillary glomerulonephritis
- Podocytopathy
- Post-infectious glomerulonephritis
- Post-infectious glomerulonephritis - Garland variety
- Pulmonary renal syndrome
- Recurrent glomerulonephritis following transplantation of kidney
- Shunt nephritis
- Transplant glomerulopathy
- Transplant glomerulopathy - early form
- Transplant glomerulopathy - late form
- Viral kidney infection
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to N05.9: its own notes plus those printed at N05, block N00-N08, and Chapter 14. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- glomerular disease NOS
- glomerulonephritis NOS
- nephritis NOS
- nephropathy NOS and renal disease NOS with morphological lesion specified in .0-.8
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- hypertensive chronic kidney disease (I12.-)
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- 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)
Code Also
A second code may be needed to fully describe the condition; the note gives no sequencing direction.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name N05.9, its category, or a range that includes it.
Excludes1 4
These codes carry an Excludes1 note naming N05.9: they are not reported together with it, unless the two conditions are unrelated.
- N00 Acute nephritic syndromenephritic syndrome NOS (N05.-) names N05.-, which includes this code
- N01 Rapidly progressive nephritic syndromenephritic syndrome NOS (N05.-) names N05.-, which includes this code
- N03 Chronic nephritic syndromenephritic syndrome NOS (N05.-) names N05.-, which includes this code
- N28.9 Disorder of kidney and ureter, unspecifiedunspecified nephritic syndrome (N05.-) names N05.-, which includes this code
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disorder (of) See Also: Disease;
glomerular (in) N05.9
Glomerulonephritis See Also: Nephritis; N05.9
poststreptococcal NEC N05.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Glomerulonephritis
inflammation of the renal glomeruli (kidney glomerulus) that can be classified by the type of glomerular injuries including antibody deposition, complement activation, cellular proliferation, and glomerulosclerosis. these structural and functional abnormalities usually lead to hematuria; proteinuria; hypertension; and renal insufficiency.Nephritis
inflammation of any part of the kidney.
Patient EducationClinical
Kidney Diseases
You have two kidneys, each about the size of your fist. They are near the middle of your back, just below the rib cage. Inside each kidney there are about a million tiny structures called nephrons. They filter your blood. They remove wastes and extra water, which become urine. The urine flows through tubes called ureters.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert N05.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About N05.9Overview
What is the ICD-10 code for unspecified nephritic syndrome with unspecified morphologic changes?
The ICD-10-CM code for unspecified nephritic syndrome with unspecified morphologic changes is N05.9 (sometimes written as N059). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is N05.9 (Unspecified nephritic syndrome) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified nephritic syndrome with unspecified morphologic changes on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does N05.9 group to?
When unspecified nephritic syndrome with unspecified morphologic changes is the principal diagnosis on an inpatient stay, it groups to MS-DRG 699, 698, 700, with relative weights from 0.6740 to 1.6400 depending on complications. Higher weights mean higher Medicare reimbursement.
Can N05.9 be reported with N28.9?
Not as a rule. The Excludes1 note at N05, which applies to N05.9, lists "nephropathy NOS with no stated morphological lesion (N28.9)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is the ICD-9 equivalent of N05.9?
Under the General Equivalence Mappings, unspecified nephritic syndrome with unspecified morphologic changes converts to ICD-9-CM 583.0 (proliferat nephritis NOS), 583.4 (rapidly prog nephrit NOS), and 583.9 (nephritis NOS). The mapping is approximate, so confirm the match fits the documentation.
Does N05.9 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage: N05.9 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the ESRD (V21) category 141 (Nephritis).
