2027 ICD-10-CM Diagnosis Code M12.20Villonodular synovitis (pigmented), unspecified site
ICD-10-CM Codes›M00–M99›M05-M14›M12
- Billable — Valid for Submission
- Not Chronic
M12.20 is a billable ICD-10-CM diagnosis code for villonodular synovitis (pigmented), unspecified site. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Tendon and synovial disorders.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Diffuse tenosynovial giant cell tumor
- Diffuse tenosynovial giant cell tumor of lower limb
- Diffuse tenosynovial giant cell tumor of tendon sheath
- Diffuse tenosynovial giant cell tumor of upper arm
- Diffuse tenosynovial giant cell tumor of upper limb
- Neoplasm of uncertain behavior of upper arm
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to M12.20: 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.
- 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.
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.
- 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.
- 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 M12.20, its category, or a range that includes it.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 M12.20 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M12.20Overview
What is the ICD-10 code for villonodular synovitis (pigmented), unspecified site?
The ICD-10-CM code for villonodular synovitis (pigmented), unspecified site is M12.20 (sometimes written as M1220). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is M12.20 (Villonodular synovitis (pigmented)) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report villonodular synovitis (pigmented), unspecified site on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does M12.20 group to?
When villonodular synovitis (pigmented), unspecified site 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 M12.20 be reported with J38.7?
Not as a rule. The Excludes1 note at M12, which applies to M12.20, 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 M12.20?
Under the General Equivalence Mappings, villonodular synovitis (pigmented), unspecified site converts to ICD-9-CM 719.20 (villonod synovit-unspec). The mapping is a direct match.
