Question 1

What is ICD-10 code M20.012?

Accepted Answer

M20.012 is the ICD-10-CM diagnosis code for mallet finger of left finger(s). A deformity of the left finger(s) where the fingertip bends downward permanently, usually caused by injury to the tendon. M20.012 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering other joint disorders (m20-m25).

M20.012 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.

Common in sports injuries and trauma; correlate with injury history in documentation.

Question 2

Is M20.012 an HCC code?

Accepted Answer

No. M20.012 is a billable ICD-10-CM code but does not map to any payment HCC category under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can still be reported on Medicare Advantage encounter data submissions, but it does not contribute to the beneficiary's Risk Adjustment Factor (RAF) score and therefore does not affect the risk-adjusted capitation payment to the plan. V28 reached 100% phase-in for payment year 2026.

Question 3

Is M20.012 billable?

Accepted Answer

Yes. M20.012 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. M20.012 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Question 4

What is the V28 vs V24 difference for M20.012?

Accepted Answer

M20.012 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards M20.012 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

Question 5

What should coders know when reporting M20.012?

Accepted Answer

Common in sports injuries and trauma; correlate with injury history in documentation Distinguish from boutonnière deformity, which affects the middle joint instead of the tip

HCC Buddy Code Card

M20.012

Is M20.012 an HCC code?

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Open M20.012 in the Interactive Encoder

M20.012 ICD-10-CM Code: Mallet finger of left finger(s)

HCC Buddy Code Card

M20.012

Is M20.012 an HCC code?

What This Code Means

Coding Tips

Child Codes

Code Hierarchy

Open M20.012 in the Interactive Encoder