2026 ICD-10-CM Diagnosis Code N80.9Endometriosis, unspecified

ICD-10-CM Codes›N00–N99›N80-N98›N80

ICD-10-CM N80.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

N80.9 is a billable ICD-10-CM diagnosis code for endometriosis, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 742 through 743, 760 through 761. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Endometriosis.

Code Identity

ICD-10-CM Code
N80.9
Billable Status
Yes — Valid for Submission
Code Describes
Endometriosis, unspecified
Short Description
Endometriosis, unspecified
Same as the full description in the CMS dataset.
Parent Code
N80
Endometriosis

Code Classification

ChapterN00–N99Diseases of the genitourinary system
SectionN80-N98Noninflammatory disorders of female genital tract
CategoryN80Endometriosis
This CodeN80.9Endometriosis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Adhesions due to endometriosis
  • Adhesions of rectovaginal pouch due to endometriosis
  • Adnexal adhesions due to endometriosis
  • Deciduomatosis
  • Dense adhesions of rectovaginal pouch due to endometriosis
  • Dense adnexal adhesions due to endometriosis
  • Endometriosis
  • Endometriosis of pelvis
  • Female infertility due to endometriosis
  • Female pelvic peritoneal adhesions
  • Filmy adhesions of rectovaginal pouch due to endometriosis
  • Filmy uterine adnexal adhesions due to endometriosis

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
    • Implant, endometrial

Clinical ClassificationClinical

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

CCSR GEN019
Endometriosis
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Endometriosis

    a condition in which functional endometrial tissue is present outside the uterus. it is often confined to the pelvis involving the ovary, the ligaments, cul-de-sac, and the uterovesical peritoneum.

Patient EducationClinical

Endometriosis

The uterus, or womb, is the place where a fetus grows during pregnancy. The uterus is lined with tissue (endometrium). Endometriosis is a disease in which tissue like the lining of the uterus grows in other places in your body. These patches of tissue are called "implants," "nodules," or "lesions." They are most often found:

The full article covers:

  • What is endometriosis?
  • What causes endometriosis?
  • Who is at risk for endometriosis?
  • What are the symptoms of endometriosis?
  • How is endometriosis diagnosed?
  • What are the treatments for endometriosis?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert N80.9 to ICD-9-CMHistory

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

ICD-9-CM
617.9 Endometriosis NOS
Exact Match The mapping is direct, with no qualifiers.

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 N80.9Overview

Is N80.9 (Endometriosis) a billable code?

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

What MS-DRG does N80.9 group to?

When endometriosis, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 742, 743, 760, 761, with relative weights from 0.5696 to 1.8348 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of N80.9?

Under the General Equivalence Mappings, endometriosis, unspecified converts to ICD-9-CM 617.9 (endometriosis NOS). The mapping is a direct match.

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.