Is M65.90 a billable ICD-10-CM code?

Yes. M65.90 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does M65.90 sit in the tabular list?

Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Disorders of synovium and tendon (M65-M67).

What cannot be coded together with M65.90?

M65.90 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above M65.90 (M65) and apply to it just the same.

M65.90

M65.90 — Unspecified synovitis and tenosynovitis, unspecified site

Billable / specific codeICD-10-CM

M65.90 is a billable, specific ICD-10-CM code for unspecified synovitis and tenosynovitis, unspecified site. It is valid for submission on a claim.

Excludes1 inherited from the categories above M65.90

These are not written on M65.90, but they bind it: a note on a category applies to every code beneath it. Billing M65.90 with anything listed here is a denial.

Written on M65 — Synovitis and tenosynovitis

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.-)

Risk adjustment

M65.90 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

M65.90 is named in 14 Medicare coverage policies — 7 listing it as supporting medical necessity, and 7 listing it as NOT covered. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A58865Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
A58883Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
A58893Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
A59374Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered

How M65.90 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to M65.90.

Synovitis
Tenosynovitis

Code history

What changed, and when. Derived by diffing consecutive CMS release files — which matters when you are defending a code assigned under an earlier edition.

addedFY2024-FY2026
Unspecified synovitis and tenosynovitis, unspecified site

Related codes at this level

Codes that share M65.9. If M65.90 is not quite right, the correct code is usually one of these.

Questions about M65.90

Is M65.90 a billable ICD-10-CM code?: Yes. M65.90 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does M65.90 sit in the tabular list?: Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Disorders of synovium and tendon (M65-M67).
What cannot be coded together with M65.90?: M65.90 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above M65.90 (M65) and apply to it just the same.