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ICD-10-CM 2027 diagnosis code

M65.9Synovitis and tenosynovitis, unspecified

Not billable — use a more specific code

M65.9 is a header code, so it can't be reported by itself. Choose one of the 10 more specific codes beneath it.

Code last changed in FY2025 (effective October 1, 2024). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About M65.9

M65.9 is the ICD-10-CM diagnosis code for synovitis and tenosynovitis, unspecified. It belongs to category M65 (synovitis and tenosynovitis), block M65-M67 (disorders of synovium and tendon) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is a header code, so it can't be reported by itself; one of its 10 subcodes must be used instead.

Within M65, choose M65.9 (unspecified) only when documentation doesn't support a more specific option: abscess of tendon sheath (M65.0), other infective (teno)synovitis (M65.1), Calcific tendinitis (M65.2), Trigger finger (M65.3), radial styloid tenosynovitis [de Quervain] (M65.4) and other synovitis and tenosynovitis (M65.8).

To report this condition, pick the subcode that matches the documentation: M65.90 (site), M65.91 (shoulder), M65.92 (arm), M65.93 (forearm), M65.94 (hand), M65.95 (thigh), M65.96 (leg), M65.97 (foot) and 2 more.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2025 (expanded into subcodes).

Before ICD-10, this condition was coded in ICD-9-CM as 727.00 (synovitis and tenosynovitis, unspecified).

Specific codes under M65.9

Notes that apply from higher levels

Instructions written at a parent level also apply to M65.9.

› From M65 Synovitis and tenosynovitis
Excludes1
  • 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.-)

Broader instructions also apply from Chapter 13: Diseases of the musculoskeletal system and connective tissue.

ICD-9-CM equivalent

Converter →
  • 727.00Synovitis and tenosynovitis, unspecifiedexact

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • FY2025 (effective 10/1/2024): Expanded — no longer billable

Common questions about M65.9

Is M65.9 billable?

No. M65.9 is a header code. Report one of its more specific subcodes instead.

What is the ICD-9 code for M65.9?

The CMS General Equivalence Mappings map M65.9 to ICD-9-CM 727.00.