2027 ICD-10-CM Diagnosis Code N03.9Chronic nephritic syndrome with unspecified morphologic changes

ICD-10-CM Codes›N00–N99›N00-N08›N03

ICD-10-CM N03.9
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

N03.9 is a billable ICD-10-CM diagnosis code for chronic 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. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 277 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nephritis; nephrosis; renal sclerosis.

N03.9 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

ICD-10-CM Code
N03.9
Billable Status
Yes — Valid for Submission
Code Describes
Chronic nephritic syndrome with unspecified morphologic changes
Short Description
Chronic nephritic syndrome with unsp morphologic changes
Parent Code
N03
Chronic nephritic syndrome

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN00-N08Glomerular diseases
CategoryN03Chronic nephritic syndrome
This CodeN03.9Chronic nephritic syndrome with unspecified morphologic changes

Medicare Risk Adjustment (HCC)Billing

N03.9 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.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
no payment category in the model that pays 100% of MA risk scores
Prior Model (CMS-HCC V24)
Not mapped under V24
this diagnosis newly risk-adjusts under the V28 model
Other CMS Models
ESRD (V21): HCC 141
ESRD V21 weights: 0.000 dialysis, 0.000 functioning graft
Part D (RxHCC)
Not mapped
N03.9 does not risk-adjust in the RxHCC prescription drug model

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.

  • Chronic diffuse glomerulonephritis
  • Chronic exudative glomerulonephritis
  • Chronic glomerulonephritis
  • Chronic nephritic syndrome
  • Chronic nephritis
  • Chronic radiation nephritis
  • Complement component 3 glomerulonephritis
  • Complement component 3 glomerulopathy
  • Exudative glomerulonephritis
  • Exudative nephritis
  • Morphologic change of kidney due to chronic nephritic syndrome
  • Nephritis caused by ionizing radiation
  • Secondary chronic nephritis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to N03.9: its own notes plus those printed at N03, 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.

From N03 Chronic nephritic syndrome applies to 11 codes
  • chronic glomerular disease
  • chronic glomerulonephritis
  • chronic nephritis

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From N03 Chronic nephritic syndrome applies to 11 codes
  • chronic tubulo-interstitial nephritis (N11.-)
  • diffuse sclerosing glomerulonephritis (N05.8-)
  • nephritic syndrome NOS (N05.-)
From Block N00-N08 Glomerular diseases applies to 107 codes
  • 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.

From Chapter 14 (N00-N99) Diseases of the genitourinary system applies to 838 codes
  • 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.

From Block N00-N08 Glomerular diseases applies to 107 codes
  • any associated kidney failure (N17-N19).

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR GEN001
Nephritis; nephrosis; renal sclerosis
Default principal diagnosis: inpatient Yes · outpatient Yes

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 N03.9 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
582.9 Chronic nephritis NOS
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About N03.9Overview

What is the ICD-10 code for chronic nephritic syndrome with unspecified morphologic changes?

The ICD-10-CM code for chronic nephritic syndrome with unspecified morphologic changes is N03.9 (sometimes written as N039). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is N03.9 (Chronic nephritic syndrome) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report chronic nephritic syndrome with unspecified morphologic changes on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does N03.9 group to?

When chronic 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.

Is N03.9 a CC or MCC?

CMS lists N03.9 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 277 closely related codes in its exclusion list.

Can N03.9 be reported with a code from N11?

Not as a rule. The Excludes1 note at N03, which applies to N03.9, lists "chronic tubulo-interstitial nephritis (N11.-)". 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).

Does N03.9 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage: N03.9 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the ESRD (V21) category 141 (Nephritis).