M66.332
BillableSpontaneous rupture of flexor tendons, left forearm
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M66.332 an HCC code?
No. M66.332 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
M66.332 is the ICD-10-CM diagnosis code for spontaneous rupture of flexor tendons, left forearm. The flexor tendons in the left forearm spontaneously tear or rupture without a specific injury or trauma. M66.332 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering disorders of synovium and tendon (m65-m67).
M66.332 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Confirm laterality is clearly documented as left forearm in the clinical notes.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for M66.332 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm laterality is clearly documented as left forearm in the clinical notes
- •Assess and document functional loss in finger and wrist flexion on the left side