2027 ICD-10-CM Diagnosis Code M12.259Villonodular synovitis (pigmented), unspecified hip

ICD-10-CM Codes›M00–M99›M05-M14›M12

ICD-10-CM M12.259
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

M12.259 is a billable ICD-10-CM diagnosis code for villonodular synovitis (pigmented), unspecified hip. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 553 through 554. Coders also document this condition as diffuse tenosynovial giant cell tumor of hip joint. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Tendon and synovial disorders.

Code Identity

ICD-10-CM Code
M12.259
Billable Status
Yes — Valid for Submission
Code Describes
Villonodular synovitis (pigmented), unspecified hip
Short Description
Villonodular synovitis (pigmented), unspecified hip
Same as the full description in the CMS dataset.
Parent Code
Villonodular synovitis (pigmented), hip

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM05-M14Inflammatory polyarthropathies
CategoryM12Other and unspecified arthropathy
This CodeM12.259Villonodular synovitis (pigmented), unspecified hip

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Diffuse tenosynovial giant cell tumor of hip joint
  • Diffuse tenosynovial giant cell tumor of sacroiliac joint
  • Lesion of joint capsule of pelvic region
  • Mass of hip joint
  • Neoplasm of sacroiliac joint
  • Neoplasm of uncertain behavior of sacrococcygeal region
  • Neoplasm of uncertain behavior of soft tissues of hip
  • Neoplasm of uncertain behavior of soft tissues of pelvis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to M12.259: its own notes plus those printed at M12, block M00-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

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From M12 Other and unspecified arthropathy applies to 169 codes

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 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.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name M12.259, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming M12.259: they are not reported together with it, unless the two conditions are unrelated.

  • M67.2 Synovial hypertrophy, not elsewhere classified
    villonodular synovitis (pigmented) (M12.2-) names M12.2-, which includes this code

Clinical ClassificationClinical

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

CCSR MUS009
Tendon and synovial disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Synovitis, Pigmented Villonodular

    diffuse outgrowth arising from the synovial membrane; synovial bursa; or tendon sheath around the joint cavity, with extension to surrounding soft tissue. it is characterized by pigmented hemosiderin-containing macrophages; foam cells; and multinucleated giant cells. it usually occurs in the hands and feet, and around large joints, such as in the ankle and knee joints.

Patient EducationClinical

Joint Disorders

Your joints are places where two or more bones come together. Your shoulders, elbows, hips, knees, and knuckles are all joints. Your spine has joints, too.

The full article covers:

  • What are joints?
  • What are joint disorders?
  • What diseases can affect the joints?
  • What types of joint disorders happen from sudden injuries?
  • What types of joint disorders happen from overuse?
  • How can I keep my joints healthy?

Read the full article at MedlinePlus

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

Convert M12.259 to ICD-9-CMHistory

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

ICD-9-CM
719.25 Villonod synovit-pelvis
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 M12.259Overview

What is the ICD-10 code for villonodular synovitis (pigmented), unspecified hip?

The ICD-10-CM code for villonodular synovitis (pigmented), unspecified hip is M12.259 (sometimes written as M12259). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is M12.259 (Villonodular synovitis (pigmented), hip) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report villonodular synovitis (pigmented), unspecified hip on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does M12.259 group to?

When villonodular synovitis (pigmented), unspecified hip is the principal diagnosis on an inpatient stay, it groups to MS-DRG 554, 553, with relative weights from 0.8328 to 1.2492 depending on complications. Higher weights mean higher Medicare reimbursement.

Can M12.259 be reported with J38.7?

Not as a rule. The Excludes1 note at M12, which applies to M12.259, lists "cricoarytenoid arthropathy (J38.7)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is the ICD-9 equivalent of M12.259?

Under the General Equivalence Mappings, villonodular synovitis (pigmented), unspecified hip converts to ICD-9-CM 719.25 (villonod synovit-pelvis). The mapping is approximate, so confirm the match fits the documentation.