2026 ICD-10-CM Diagnosis Code N80.512Deep endometriosis of the rectum

ICD-10-CM Codes›N00–N99›N80-N98›N80

ICD-10-CM N80.512
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N80.512 is a billable ICD-10-CM diagnosis code for deep endometriosis of the rectum. 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 deep endometriosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Endometriosis.

Code Identity

ICD-10-CM Code
N80.512
Billable Status
Yes — Valid for Submission
Code Describes
Deep endometriosis of the rectum
Short Description
Deep endometriosis of the rectum
Same as the full description in the CMS dataset.
Parent Code
N80.51
Endometriosis of the rectum

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN80-N98Noninflammatory disorders of female genital tract
CategoryN80Endometriosis
This CodeN80.512Deep endometriosis of the rectum

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Deep endometriosis
  • Deep endometriosis of rectum
  • Endometriosis of large intestine
  • Endometriosis of rectum

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Deep endometriosis of the rectum, multifocal

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.

    • Endometriosis
      • rectum
        • deep (multifocal)

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 N80.512 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 N80.512Overview

Is N80.512 (Endometriosis of the rectum) a billable code?

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

What MS-DRG does N80.512 group to?

When deep endometriosis of the rectum 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.

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.