M25.40
✓ BillableEffusion, unspecified joint
Diseases of the musculoskeletal system and connective tissue (M00-M99)
❌ Excludes1
inheritedRules inherited from parent codes in the hierarchy.
- • hydrarthrosis in yaws (A66.6)
- • intermittent hydrarthrosis (M12.4-)
- • other infective (teno)synovitis (M65.1-)
⚠️ Excludes2
inheritedRules inherited from parent codes.
- • 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-)
Clinical Description
ICD-10-CM code M25.40 represents effusion, unspecified joint. This code falls under the Diseases of the musculoskeletal system and connective tissue (M00-M99) classification. It is a billable/specific code valid for HIPAA-covered transactions as of October 1, 2025 (FY2026). This code can be used to indicate a diagnosis for reimbursement purposes on insurance claims.
This is a 6-character code at the 5th level of specificity. This is the most specific code available in this subcategory. Coders should note that M25.40 has 3 Excludes1 restriction(s) — codes that cannot be reported together on the same claim.
Frequently Asked Questions
What is ICD-10 code M25.40?
ICD-10-CM code M25.40 is "Effusion, unspecified joint". It belongs to the category: Diseases of the musculoskeletal system and connective tissue (M00-M99).
Is M25.40 a billable ICD-10 code?
Yes, M25.40 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
What codes are excluded with M25.40?
M25.40 has 3 Excludes1 rule(s). These codes are mutually exclusive and cannot be coded together on the same claim.
Can M25.40 be coded with other codes?
M25.40 has 7 Excludes2 note(s). These conditions can be coded together if both are documented in the patient record.
Related Codes in M25.4
Other codes in the same category that may be relevant for differential coding:
🧪 Validate Combinations
Add M25.40 to the Excludes Checker to validate against your full code list.
Open in Checker →Code Information
Data Source
CMS ICD-10-CM 2026 Tabular List
Updated October 1, 2025 (FY2026)