ICD-10 Code for Synovitis
The ICD-10-CM code for synovitis is M65.90 — Unspecified synovitis and tenosynovitis, unspecified site. This is the code the Alphabetic Index gives for synovitis with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
M65.90 is billable but unspecified. If the documentation names a type, site or cause, one of the more specific codes below is likely expected.
Which synovitis code should you use?
The Alphabetic Index lists 36 codes under Synovitis. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
| ankle and foot | M65.97 | Unspecified synovitis and tenosynovitis, ankle and foot | not billable |
| arm, upper | M65.92 | Unspecified synovitis and tenosynovitis, upper arm | not billable |
| forearm | M65.93 | Unspecified synovitis and tenosynovitis, forearm | not billable |
| gonococcal | A54.49 | Gonococcal infection of other musculoskeletal tissue | |
| hand | M65.94 | Unspecified synovitis and tenosynovitis, hand | not billable |
| leg, lower | M65.96 | Unspecified synovitis and tenosynovitis, lower leg | not billable |
| multiple sites, unspecified type | M65.99 | Unspecified synovitis and tenosynovitis, multiple sites | |
| shoulder | M65.91 | Unspecified synovitis and tenosynovitis, shoulder | not billable |
| specified site, unspecified type | M65.98 | Unspecified synovitis and tenosynovitis, other site | |
| syphilitic | A52.78 | Syphilis of other musculoskeletal tissue | |
| thigh | M65.95 | Unspecified synovitis and tenosynovitis, thigh | not billable |
| transient | M67.3 | Transient synovitis | not billable |
| villonodular | M12.2 | Villonodular synovitis (pigmented) | not billable |
Synovitis crepitant
Synovitis in
Synovitis syphilitic
| congenital | A50.02 | Early congenital syphilitic osteochondropathy |
Synovitis transient
| ankle | M67.37 | Transient synovitis, ankle and foot | not billable |
| elbow | M67.32 | Transient synovitis, elbow | not billable |
| foot joint | M67.37 | Transient synovitis, ankle and foot | not billable |
| hand joint | M67.34 | Transient synovitis, hand | not billable |
| hip | M67.35 | Transient synovitis, hip | not billable |
| knee | M67.36 | Transient synovitis, knee | not billable |
| multiple site | M67.39 | Transient synovitis, multiple sites | |
| pelvic region | M67.35 | Transient synovitis, hip | not billable |
| shoulder | M67.31 | Transient synovitis, shoulder | not billable |
| specified joint NEC | M67.38 | Transient synovitis, other site | |
| wrist | M67.33 | Transient synovitis, wrist | not billable |
Synovitis villonodular
| ankle | M12.27 | Villonodular synovitis (pigmented), ankle and foot | not billable |
| elbow | M12.22 | Villonodular synovitis (pigmented), elbow | not billable |
| foot joint | M12.27 | Villonodular synovitis (pigmented), ankle and foot | not billable |
| hand joint | M12.24 | Villonodular synovitis (pigmented), hand | not billable |
| hip | M12.25 | Villonodular synovitis (pigmented), hip | not billable |
| knee | M12.26 | Villonodular synovitis (pigmented), knee | not billable |
| multiple site | M12.29 | Villonodular synovitis (pigmented), multiple sites | |
| pelvic region | M12.25 | Villonodular synovitis (pigmented), hip | not billable |
| shoulder | M12.21 | Villonodular synovitis (pigmented), shoulder | not billable |
| specified joint NEC | M12.28 | Villonodular synovitis (pigmented), other specified site | |
| vertebrae | M12.28 | Villonodular synovitis (pigmented), other specified site | |
| wrist | M12.23 | Villonodular synovitis (pigmented), wrist | not billable |
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources