2026 ICD-10-CM Diagnosis Code M65Synovitis and tenosynovitis

ICD-10-CM Codes›M00–M99›M65-M67›M65

ICD-10-CM M65
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

M65 is a non-billable ICD-10-CM category code for synovitis and tenosynovitis, so it cannot be submitted on claims. Use a more specific code from this category instead, such as M65.00, M65.011, M65.012, and M65.019.

Code Identity

ICD-10-CM Code
M65
Billable Status
No — Non-Billable Category
Code Describes
Synovitis and tenosynovitis
Short Description
Synovitis and tenosynovitis
Same as the full description in the CMS dataset.
Chapter
M65-M67
Disorders of synovium and tendon

Code Classification

ChapterM00–M99Diseases of the musculoskeletal system and connective tissue
SectionM65-M67Disorders of synovium and tendon
CategoryM65Synovitis and tenosynovitis
This CodeM65Synovitis and tenosynovitis

Specific Coding for Synovitis and tenosynovitisOverview

Non-specific codes like M65 require more characters. Use one of these billable codes instead:

  • M65.0 for Abscess of tendon sheath

  • Use M65.00 for Abscess of tendon sheath, unspecified site

  • M65.01 for Abscess of tendon sheath, shoulder

  • M65.02 for Abscess of tendon sheath, upper arm

  • M65.03 for Abscess of tendon sheath, forearm

  • M65.04 for Abscess of tendon sheath, hand

  • M65.05 for Abscess of tendon sheath, thigh

  • M65.06 for Abscess of tendon sheath, lower leg

  • M65.07 for Abscess of tendon sheath, ankle and foot

  • Use M65.08 for Abscess of tendon sheath, other site

  • M65.1 for Other infective (teno)synovitis

  • Use M65.10 for Other infective (teno)synovitis, unspecified site

  • M65.11 for Other infective (teno)synovitis, shoulder

  • M65.12 for Other infective (teno)synovitis, elbow

  • M65.13 for Other infective (teno)synovitis, wrist

  • M65.14 for Other infective (teno)synovitis, hand

  • M65.15 for Other infective (teno)synovitis, hip

  • M65.16 for Other infective (teno)synovitis, knee

  • M65.17 for Other infective (teno)synovitis, ankle and foot

  • Use M65.18 for Other infective (teno)synovitis, other site

  • Use M65.19 for Other infective (teno)synovitis, multiple sites

  • M65.2 for Calcific tendinitis

  • Use M65.20 for Calcific tendinitis, unspecified site

  • M65.22 for Calcific tendinitis, upper arm

  • M65.23 for Calcific tendinitis, forearm

  • M65.24 for Calcific tendinitis, hand

  • M65.25 for Calcific tendinitis, thigh

  • M65.26 for Calcific tendinitis, lower leg

  • M65.27 for Calcific tendinitis, ankle and foot

  • Use M65.28 for Calcific tendinitis, other site

  • Use M65.29 for Calcific tendinitis, multiple sites

  • M65.3 for Trigger finger

  • Use M65.30 for Trigger finger, unspecified finger

  • M65.31 for Trigger thumb

  • M65.32 for Trigger finger, index finger

  • M65.33 for Trigger finger, middle finger

  • M65.34 for Trigger finger, ring finger

  • M65.35 for Trigger finger, little finger

  • Use M65.4 for Radial styloid tenosynovitis [de Quervain]

  • M65.8 for Other synovitis and tenosynovitis

  • Use M65.80 for Other synovitis and tenosynovitis, unspecified site

  • M65.81 for Other synovitis and tenosynovitis, shoulder

  • M65.82 for Other synovitis and tenosynovitis, upper arm

  • M65.83 for Other synovitis and tenosynovitis, forearm

  • M65.84 for Other synovitis and tenosynovitis, hand

  • M65.85 for Other synovitis and tenosynovitis, thigh

  • M65.86 for Other synovitis and tenosynovitis, lower leg

  • M65.87 for Other synovitis and tenosynovitis, ankle and foot

  • Use M65.88 for Other synovitis and tenosynovitis, other site

  • Use M65.89 for Other synovitis and tenosynovitis, multiple sites

  • M65.9 for Synovitis and tenosynovitis, unspecified

  • Use M65.90 for Unspecified synovitis and tenosynovitis, unspecified site

  • M65.91 for Unspecified synovitis and tenosynovitis, shoulder

  • M65.92 for Unspecified synovitis and tenosynovitis, upper arm

  • M65.93 for Unspecified synovitis and tenosynovitis, forearm

  • M65.94 for Unspecified synovitis and tenosynovitis, hand

  • M65.95 for Unspecified synovitis and tenosynovitis, thigh

  • M65.96 for Unspecified synovitis and tenosynovitis, lower leg

  • M65.97 for Unspecified synovitis and tenosynovitis, ankle and foot

  • Use M65.98 for Unspecified synovitis and tenosynovitis, other site

  • Use M65.99 for Unspecified synovitis and tenosynovitis, multiple sites

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 1 Excludes

  • chronic crepitant synovitis of hand and wrist M70.0
  • current injury - see injury of ligament or tendon by body region
  • soft tissue disorders related to use, overuse and pressure M70

Patient EducationClinical

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Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About M65Overview

Is M65 (Synovitis and tenosynovitis) a billable code?

No. This is a category header that groups the codes for synovitis and tenosynovitis, and headers cannot be submitted on claims. Claims for synovitis and tenosynovitis need a more specific code from this category, such as M65.00, M65.011, and M65.012.