2026 ICD-10-CM Diagnosis Code N26.1Atrophy of kidney (terminal)

ICD-10-CM Codes›N00–N99›N25-N29›N26

ICD-10-CM N26.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N26.1 is a billable ICD-10-CM diagnosis code for atrophy of kidney (terminal). It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 698 through 700. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified diseases of kidney and ureters.

Code Identity

ICD-10-CM Code
N26.1
Billable Status
Yes — Valid for Submission
Code Describes
Atrophy of kidney (terminal)
Short Description
Atrophy of kidney (terminal)
Same as the full description in the CMS dataset.
Parent Code
N26
Unspecified contracted kidney

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN25-N29Other disorders of kidney and ureter
CategoryN26Unspecified contracted kidney
This CodeN26.1Atrophy of kidney (terminal)

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Atrophy of cortex of kidney
  • Atrophy of kidney
  • Atrophy of left kidney
  • Atrophy of renal tubule
  • Atrophy of right kidney
  • Bilateral atrophy of kidney

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Atrophy, atrophic(of)
      • kidney (senile) (terminal)
    • Atrophy, atrophic(of)
      • renal

Clinical ClassificationClinical

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

CCSR GEN006
Other specified and unspecified diseases of kidney and ureters
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 N26.1 to ICD-9-CMHistory

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

ICD-9-CM
587 Renal sclerosis 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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About N26.1Overview

Is N26.1 (Unspecified contracted kidney) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report atrophy of kidney (terminal) on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does N26.1 group to?

When atrophy of kidney (terminal) is the principal diagnosis on an inpatient stay, it groups to MS-DRG 698, 699, 700, with relative weights from 0.6899 to 1.6544 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of N26.1?

Under the General Equivalence Mappings, atrophy of kidney (terminal) converts to ICD-9-CM 587 (renal sclerosis NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.