2027 ICD-10-CM Diagnosis Code M25.10Fistula, unspecified joint

ICD-10-CM Codes›M00–M99›M20-M25›M25

ICD-10-CM M25.10
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

M25.10 is a billable ICD-10-CM diagnosis code for fistula, unspecified joint. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 555 through 556. Coders also document this condition as fistula of joint. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified joint disorders.

Code Identity

ICD-10-CM Code
M25.10
Billable Status
Yes — Valid for Submission
Code Describes
Fistula, unspecified joint
Short Description
Fistula, unspecified joint
Same as the full description in the CMS dataset.
Parent Code
Fistula of joint

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM20-M25Other joint disorders
CategoryM25Other joint disorder, not elsewhere classified
This CodeM25.10Fistula, unspecified joint

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Fistula of joint

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to M25.10: its own notes plus those printed at M25, block M00-M25, block M20-M25, and Chapter 13. 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 Block M00-M25 applies to 2,249 codes
  • Disorders affecting predominantly peripheral (limb) joints

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 M25 Other joint disorder, not elsewhere classified applies to 225 codes
  • abnormality of gait and mobility (R26.-)
  • acquired deformities of limb (M20-M21)
  • calcification of bursa (M71.4-)
  • calcification of shoulder (joint) (M75.3)
  • calcification of tendon (M65.2-)
  • difficulty in walking (R26.2)
  • temporomandibular joint disorder (M26.6-)
From Block M20-M25 Other joint disorders applies to 719 codes
From Chapter 13 (M00-M99) Diseases of the musculoskeletal system and connective tissue applies to 6,687 codes
  • arthropathic psoriasis (L40.5-)
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • compartment syndrome (traumatic) (T79.A-)
  • 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)

Notes

General instructions on how these codes are used.

From Chapter 13 (M00-M99) Diseases of the musculoskeletal system and connective tissue applies to 6,687 codes
  • Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition

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 MUS007
Other specified joint disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Fistula

    abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body.

Patient EducationClinical

Fistulas

A fistula is an abnormal connection between two parts inside of the body. Fistulas may develop between different organs, such as between the esophagus and the windpipe or the bowel and the vagina. They can also develop between two blood vessels, such as between an artery and a vein or between two arteries.

Read the full article at MedlinePlus

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

Convert M25.10 to ICD-9-CMHistory

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

ICD-9-CM
719.80 Joint dis NEC-unspec
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 M25.10Overview

What is the ICD-10 code for fistula, unspecified joint?

The ICD-10-CM code for fistula, unspecified joint is M25.10 (sometimes written as M2510). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is M25.10 (Fistula of joint) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report fistula, unspecified joint on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does M25.10 group to?

When fistula, unspecified joint is the principal diagnosis on an inpatient stay, it groups to MS-DRG 555, 556, with relative weights from 0.8210 to 1.2908 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of M25.10?

Under the General Equivalence Mappings, fistula, unspecified joint converts to ICD-9-CM 719.80 (joint dis NEC-unspec). The mapping is approximate, so confirm the match fits the documentation.