ICD-10-CM 2027 diagnosis code
M65.1Other infective (teno)synovitis
M65.1 is a header code, so it can't be reported by itself. Choose one of the 10 more specific codes beneath it.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About M65.1
M65.1 is the ICD-10-CM diagnosis code for other infective (teno)synovitis. 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 M65.1 (Other infective (teno)synovitis) only when documentation doesn't support a more specific option: abscess of tendon sheath (M65.0), Calcific tendinitis (M65.2), Trigger finger (M65.3), radial styloid tenosynovitis [de Quervain] (M65.4), other synovitis and tenosynovitis (M65.8) and unspecified (M65.9).
To report this condition, pick the subcode that matches the documentation: M65.10 (unspecified site), M65.11 (shoulder), M65.12 (elbow), M65.13 (wrist), M65.14 (hand), M65.15 (hip), M65.16 (knee), M65.17 (ankle and foot) and 2 more.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Specific codes under M65.1
- M65.10Other infective (teno)synovitis, unspecified siteBillable
- M65.11Other infective (teno)synovitis, shoulder
- M65.12Other infective (teno)synovitis, elbow
- M65.13Other infective (teno)synovitis, wrist
- M65.14Other infective (teno)synovitis, hand
- M65.15Other infective (teno)synovitis, hip
- M65.16Other infective (teno)synovitis, knee
- M65.17Other infective (teno)synovitis, ankle and foot
- M65.18Other infective (teno)synovitis, other siteBillable
- M65.19Other infective (teno)synovitis, multiple sitesBillable
Notes that apply from higher levels
Instructions written at a parent level also apply to M65.1.
Broader instructions also apply from Chapter 13: Diseases of the musculoskeletal system and connective tissue.
Alphabetic index entries
1 entriesTerms in the official ICD-10-CM index that lead to M65.1.
Codes whose notes reference M65.1
- M25.4Excludes1
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about M65.1
Is M65.1 billable?
- No. M65.1 is a header code. Report one of its more specific subcodes instead.