M99.86
BillableOther biomechanical lesions of lower extremity
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M99.86 an HCC code?
No. M99.86 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
M99.86 is the ICD-10-CM diagnosis code for other biomechanical lesions of lower extremity. Structural or mechanical problems in the legs and feet that affect how bones, joints, and tissues move and function. M99.86 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering biomechanical lesions, not elsewhere classified (m99).
M99.86 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.
Document the specific location (knee, ankle, foot, thigh) for clarity and potential additional specificity.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for M99.86 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.