M85.459
BillableSolitary bone cyst, unspecified pelvis
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M85.459 an HCC code?
No. M85.459 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
M85.459 is the ICD-10-CM diagnosis code for solitary bone cyst, unspecified pelvis. A noncancerous fluid-filled cavity that forms in the pelvic bone, typically discovered incidentally on imaging. M85.459 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).
M85.459 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.
Verify imaging documentation confirms solitary cyst diagnosis before coding.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for M85.459 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify imaging documentation confirms solitary cyst diagnosis before coding
- •Use this code only when the specific pelvic bone location cannot be determined