M66.38 — Spontaneous rupture of flexor tendons, other site
M66.38 is a billable, specific ICD-10-CM code for spontaneous rupture of flexor tendons, other site. It is valid for submission on a claim.
Risk adjustment
M66.38 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
M66.38 is named in 11 Medicare coverage policies — 5 listing it as supporting medical necessity, and 6 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
- 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
- A59434Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
How M66.38 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 M66.38.
- Rupture, ruptured›tendon›nontraumatic›flexor›specified site NEC
Related codes at this level
Codes that share M66.3. If M66.38 is not quite right, the correct code is usually one of these.
- M66.30Spontaneous rupture of flexor tendons, unspecified site
- M66.31Spontaneous rupture of flexor tendons, shoulder
- M66.32Spontaneous rupture of flexor tendons, upper arm
- M66.33Spontaneous rupture of flexor tendons, forearm
- M66.34Spontaneous rupture of flexor tendons, hand
- M66.35Spontaneous rupture of flexor tendons, thigh
- M66.36Spontaneous rupture of flexor tendons, lower leg
- M66.37Spontaneous rupture of flexor tendons, ankle and foot
- M66.39Spontaneous rupture of flexor tendons, multiple sites
Questions about M66.38
- Is M66.38 a billable ICD-10-CM code?
- Yes. M66.38 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does M66.38 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).