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M85.129

Billable

Skeletal fluorosis, unspecified upper arm

Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)

Is M85.129 an HCC code?

No. M85.129 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

M85.129 is the ICD-10-CM diagnosis code for skeletal fluorosis, unspecified upper arm. A condition where fluorine accumulates in the bones of the upper arm when the specific side (left or right) is not documented or is bilateral. M85.129 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering disorders of bone density and structure (m80-m85).

M85.129 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.

Use this code only when laterality cannot be determined from documentation or when bilateral involvement exists.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for M85.129 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • Use this code only when laterality cannot be determined from documentation or when bilateral involvement exists
  • Query the provider if documentation is unclear about which arm is affected to ensure accurate coding

Code Hierarchy

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