2026 ICD-10-CM Diagnosis Code N80.541Superficial endometriosis of the appendix

ICD-10-CM Codes›N00–N99›N80-N98›N80

ICD-10-CM N80.541
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N80.541 is a billable ICD-10-CM diagnosis code for superficial endometriosis of the appendix. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 391 through 392. Coders also document this condition as endometriosis of appendix. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Endometriosis.

Code Identity

ICD-10-CM Code
N80.541
Billable Status
Yes — Valid for Submission
Code Describes
Superficial endometriosis of the appendix
Short Description
Superficial endometriosis of the appendix
Same as the full description in the CMS dataset.
Parent Code
N80.54
Endometriosis of the appendix

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN80-N98Noninflammatory disorders of female genital tract
CategoryN80Endometriosis
This CodeN80.541Superficial endometriosis of the appendix

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Endometriosis of appendix
  • Endometriosis of large intestine
  • Superficial endometriosis of appendix

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 GEN019
Endometriosis
Default principal diagnosis: inpatient Yes · outpatient Yes

Code History & ChangesHistory

Replacement N80.541 replaces the following previously assigned code(s):

  • N80.5 - Endometriosis of intestine
FY 2023AddedAdded to the ICD-10-CM code setEffective October 1, 2022.
FY 2024–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About N80.541Overview

What is the ICD-10 code for superficial endometriosis of the appendix?

The ICD-10-CM code for superficial endometriosis of the appendix is N80.541 (sometimes written as N80541). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is N80.541 (Endometriosis of the appendix) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report superficial endometriosis of the appendix on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does N80.541 group to?

When superficial endometriosis of the appendix is the principal diagnosis on an inpatient stay, it groups to MS-DRG 391, 392, with relative weights from 0.7796 to 1.2683 depending on complications. Higher weights mean higher Medicare reimbursement.