Question 1

What is ICD-10 code M23.222?

Accepted Answer

M23.222 is the ICD-10-CM diagnosis code for Derangement of posterior horn of medial meniscus due to old tear or injury, left knee. It belongs to the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99). M23.222 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. M23.222 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Question 2

Is M23.222 an HCC code?

Accepted Answer

No. M23.222 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 M23.222 billable?

Accepted Answer

Yes. M23.222 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. M23.222 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 M23.222?

Accepted Answer

M23.222 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 M23.222 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 M23.222?

Accepted Answer

This code is specific to the left knee and posterior horn of medial meniscus; verify laterality in documentation before coding Ensure the tear or injury is documented as 'old' or chronic rather than acute to use this code family

M23.222

Is M23.222 an HCC code?

What This Code Means

Coding Tips

Code Hierarchy

Open M23.222 in the Interactive Encoder