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M13.172

Billable

Monoarthritis, not elsewhere classified, left ankle and foot

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

Is M13.172 an HCC code?

No. M13.172 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

M13.172 is the ICD-10-CM diagnosis code for monoarthritis, not elsewhere classified, left ankle and foot. Inflammation of a single joint in the left ankle or foot that doesn't fit into other specific arthritis categories. M13.172 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering inflammatory polyarthropathies (m05-m14).

M13.172 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 monoarthritis (single joint inflammation) is confirmed and other specific arthritis types have been ruled out.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for M13.172 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 monoarthritis (single joint inflammation) is confirmed and other specific arthritis types have been ruled out
  • The '2' indicates left side; use M13.171 for right side and M13.179 for unspecified side

Code Hierarchy

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