M65.31 – Trigger thumb

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

Non-billable header

ICD-10-CM code M65.31

Code: M65.31 (claims format: M6531)
Description: Trigger thumb
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
Parent codes: M65 › M65.3

Billable codes under M65.31

M65.31 is a header code and cannot be used on claims. Choose the most specific code:

M65.311 – Trigger thumb, right thumbBillable
M65.312 – Trigger thumb, left thumbBillable
M65.319 – Trigger thumb, unspecified thumbBillable

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

M65 – Synovitis and tenosynovitis

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.-)

M65.3 – Trigger finger

Applicable to:

Nodular tendinous disease

Index terms for M65.31

Entries in the ICD-10-CM alphabetic index that lead to this code:

Trigger finger, thumb

Related codes in M65.3

M65.30 – Trigger finger, unspecified fingerBillable
M65.32 – Trigger finger, index fingerHeader
M65.33 – Trigger finger, middle fingerHeader
M65.34 – Trigger finger, ring fingerHeader
M65.35 – Trigger finger, little fingerHeader

Frequently asked questions

What is ICD-10 code M65.31?

M65.31 is the ICD-10-CM code for trigger thumb, in the block M65-M67 (Disorders of synovium and tendon).

Is M65.31 a billable code?

No. M65.31 is a header code with more specific child codes; report one of the billable codes listed above.

What category does M65.31 belong to?

It belongs to category M65 – Synovitis and tenosynovitis.

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.