M12.40 Intermittent hydrarthrosis, unspecified site

Billable ICD-10-CM code, FY2026.

Applies from M12 Other and unspecified arthropathy

Excludes1 (never code together)

• arthrosis (M15-M19)
• cricoarytenoid arthropathy (J38.7)

MS-DRG index

Defines the logic of DRG(s) 553-554 in MDC 08.

Approximate ICD-9-CM (GEMs)

• 719.30 Palindromic rheumatism, site unspecified (approximate)

Code annotations containing back-references to M12.40

Back-references to M12.4

• Type 1 Excludes: M25.4 Effusion of joint ("intermittent hydrarthrosis (M12.4-)")

Diagnosis Index entries for M12.40

• Hydrarthrosis › intermittent

Nearby codes

• M12.372 Palindromic rheumatism, left ankle and foot
• M12.379 Palindromic rheumatism, unspecified ankle and foot
• M12.38 Palindromic rheumatism, other specified site
• M12.39 Palindromic rheumatism, multiple sites
• M12.4 Intermittent hydrarthrosis
• M12.40 Intermittent hydrarthrosis, unspecified site (this code)
• M12.41 Intermittent hydrarthrosis, shoulder
• M12.411 Intermittent hydrarthrosis, right shoulder
• M12.412 Intermittent hydrarthrosis, left shoulder
• M12.419 Intermittent hydrarthrosis, unspecified shoulder
• M12.42 Intermittent hydrarthrosis, elbow