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 | M65.1 | Other infective (teno)synovitis | not billable |
| radial styloid | M65.4 | Radial styloid tenosynovitis [de Quervain] | |
| shoulder region | M65.81 | Other synovitis and tenosynovitis, shoulder | not billable |
| specified type NEC | M65.88 | Other synovitis and tenosynovitis, other site |
Tenosynovitis in
Tenosynovitis infective NEC
| ankle | M65.17 | Other infective (teno)synovitis, ankle and foot | not billable |
| foot | M65.17 | Other infective (teno)synovitis, ankle and foot | not billable |
| forearm | M65.13 | Other infective (teno)synovitis, wrist | not billable |
| hand | M65.14 | Other infective (teno)synovitis, hand | not billable |
| lower leg | M65.16 | Other infective (teno)synovitis, knee | not billable |
| multiple sites | M65.19 | Other infective (teno)synovitis, multiple sites | |
| pelvic region | M65.15 | Other infective (teno)synovitis, hip | not billable |
| shoulder region | M65.11 | Other infective (teno)synovitis, shoulder | not billable |
| specified site NEC | M65.18 | Other infective (teno)synovitis, other site | |
| thigh | M65.15 | Other infective (teno)synovitis, hip | not billable |
| upper arm | M65.12 | Other infective (teno)synovitis, elbow | not billable |
Tenosynovitis specified type NEC
| ankle | M65.87 | Other synovitis and tenosynovitis, ankle and foot | not billable |
| foot | M65.87 | Other synovitis and tenosynovitis, ankle and foot | not billable |
| forearm | M65.83 | Other synovitis and tenosynovitis, forearm | not billable |
| hand | M65.84 | Other synovitis and tenosynovitis, hand | not billable |
| lower leg | M65.86 | Other synovitis and tenosynovitis, lower leg | not billable |
| multiple sites | M65.89 | Other synovitis and tenosynovitis, multiple sites | |
| pelvic region | M65.85 | Other synovitis and tenosynovitis, thigh | not billable |
| shoulder region | M65.81 | Other synovitis and tenosynovitis, shoulder | not billable |
| specified site NEC | M65.88 | Other synovitis and tenosynovitis, other site | |
| thigh | M65.85 | Other synovitis and tenosynovitis, thigh | not billable |
| upper arm | M65.82 | Other synovitis and tenosynovitis, upper arm | 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