NPI Atlas

M65 – Synovitis and tenosynovitis

ICD-10-CM 2027 diagnosis code · Disorders of synovium and tendon

Non-billable header

ICD-10-CM code M65

Code: M65 (claims format: M65)
Description: Synovitis and tenosynovitis
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 13. Diseases of the musculoskeletal system and connective tissue (M00-M99)
Block: M65-M67 Disorders of synovium and tendon

Billable codes under M65

M65 is a header code and cannot be used on claims. Choose the most specific code:

M65.0 – Abscess of tendon sheathHeader (more codes below)
M65.1 – Other infective (teno)synovitisHeader (more codes below)
M65.2 – Calcific tendinitisHeader (more codes below)
M65.3 – Trigger fingerHeader (more codes below)
M65.4 – Radial styloid tenosynovitis [de Quervain]Billable
M65.8 – Other synovitis and tenosynovitisHeader (more codes below)
M65.9 – Synovitis and tenosynovitis, unspecifiedHeader (more codes below)

Notes for M65

Excludes1 (not coded here):

chronic crepitant synovitis of hand and wrist (M70.0-)
current injury - see injury of ligament or tendon by body region
soft tissue disorders related to use, overuse and pressure (M70.-)

Frequently asked questions

What is ICD-10 code M65?

M65 is the ICD-10-CM code for synovitis and tenosynovitis, in the block M65-M67 (Disorders of synovium and tendon).

Is M65 a billable code?

No. M65 is a header code with more specific child codes; report one of the billable codes listed above.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.