M25.4 – Effusion of joint

ICD-10-CM 2027 diagnosis code · Other joint disorders

Non-billable header

ICD-10-CM code M25.4

Code: M25.4 (claims format: M254)
Description: Effusion of joint
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: M20-M25 Other joint disorders
Parent codes: M25

Billable codes under M25.4

M25.4 is a header code and cannot be used on claims. Choose the most specific code:

M25.40 – Effusion, unspecified jointBillable
M25.41 – Effusion, shoulderHeader (more codes below)
M25.42 – Effusion, elbowHeader (more codes below)
M25.43 – Effusion, wristHeader (more codes below)
M25.44 – Effusion, handHeader (more codes below)
M25.45 – Effusion, hipHeader (more codes below)
M25.46 – Effusion, kneeHeader (more codes below)
M25.47 – Effusion, ankle and footHeader (more codes below)
M25.48 – Effusion, other siteBillable

Notes for M25.4

Excludes1 (not coded here):

hydrarthrosis in yaws (A66.6)
intermittent hydrarthrosis (M12.4-)
other infective (teno)synovitis (M65.1-)

Notes inherited from parent codes

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

M25 – Other joint disorder, not elsewhere classified

Excludes2 (not included here):

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-)

Block M20-M25

Excludes2 (not included here):

joints of the spine (M40-M54)

Related codes in M25

M25.0 – HemarthrosisHeader
M25.1 – Fistula of jointHeader
M25.2 – Flail jointHeader
M25.3 – Other instability of jointHeader
M25.5 – Pain in jointHeader
M25.6 – Stiffness of joint, not elsewhere classifiedHeader
M25.7 – OsteophyteHeader
M25.8 – Other specified joint disordersHeader
M25.9 – Joint disorder, unspecifiedBillable

Frequently asked questions

What is ICD-10 code M25.4?

M25.4 is the ICD-10-CM code for effusion of joint, in the block M20-M25 (Other joint disorders).

Is M25.4 a billable code?

No. M25.4 is a header code with more specific child codes; report one of the billable codes listed above.

What category does M25.4 belong to?

It belongs to category M25 – Other joint disorder, not elsewhere classified.

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.