ICD-10 Code for Tenosynovitis
The ICD-10-CM code for tenosynovitis is M65.90 — Unspecified synovitis and tenosynovitis, unspecified site. This is the code the Alphabetic Index gives for tenosynovitis 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 tenosynovitis code should you use?
The Alphabetic Index lists 24 codes under Tenosynovitis. 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
| gonococcal | A54.49 | Gonococcal infection of other musculoskeletal tissue |
| infective NEC | M65.1Not billable | Other infective (teno)synovitis |
| radial styloid | M65.4 | Radial styloid tenosynovitis [de Quervain] |
| shoulder region | M65.81Not billable | Other synovitis and tenosynovitis, shoulder |
| specified type NEC | M65.88 | Other synovitis and tenosynovitis, other site |
Tenosynovitis in
Tenosynovitis infective NEC
| ankle | M65.17Not billable | Other infective (teno)synovitis, ankle and foot |
| foot | M65.17Not billable | Other infective (teno)synovitis, ankle and foot |
| forearm | M65.13Not billable | Other infective (teno)synovitis, wrist |
| hand | M65.14Not billable | Other infective (teno)synovitis, hand |
| lower leg | M65.16Not billable | Other infective (teno)synovitis, knee |
| multiple sites | M65.19 | Other infective (teno)synovitis, multiple sites |
| pelvic region | M65.15Not billable | Other infective (teno)synovitis, hip |
| shoulder region | M65.11Not billable | Other infective (teno)synovitis, shoulder |
| specified site NEC | M65.18 | Other infective (teno)synovitis, other site |
| thigh | M65.15Not billable | Other infective (teno)synovitis, hip |
| upper arm | M65.12Not billable | Other infective (teno)synovitis, elbow |
Tenosynovitis specified type NEC
| ankle | M65.87Not billable | Other synovitis and tenosynovitis, ankle and foot |
| foot | M65.87Not billable | Other synovitis and tenosynovitis, ankle and foot |
| forearm | M65.83Not billable | Other synovitis and tenosynovitis, forearm |
| hand | M65.84Not billable | Other synovitis and tenosynovitis, hand |
| lower leg | M65.86Not billable | Other synovitis and tenosynovitis, lower leg |
| multiple sites | M65.89 | Other synovitis and tenosynovitis, multiple sites |
| pelvic region | M65.85Not billable | Other synovitis and tenosynovitis, thigh |
| shoulder region | M65.81Not billable | Other synovitis and tenosynovitis, shoulder |
| specified site NEC | M65.88 | Other synovitis and tenosynovitis, other site |
| thigh | M65.85Not billable | Other synovitis and tenosynovitis, thigh |
| upper arm | M65.82Not billable | Other synovitis and tenosynovitis, upper arm |
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