Question 1

What is ICD-10 code M79.669?

Accepted Answer

M79.669 is the ICD-10-CM diagnosis code for pain in unspecified lower leg. Pain in the lower leg when the specific side is not documented or when both legs are affected. M79.669 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering other soft tissue disorders (m70-m79).

M79.669 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 only when laterality is truly unspecified in the medical record.

Question 2

Is M79.669 an HCC code?

Accepted Answer

No. M79.669 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 M79.669 billable?

Accepted Answer

Yes. M79.669 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. M79.669 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

Which HCC does M79.669 map to under V28?

Accepted Answer

M79.669 does not map to a CMS-HCC V28 payment category. Check the current CMS-HCC V28 model file for payment year 2026 rather than an older V24 tip sheet.

Question 5

What does M79.669 pay in RAF?

Accepted Answer

M79.669 has no separately stated V28 community RAF weight. If it is not a V28 payment HCC, it adds nothing to a community RAF score.

Question 6

What is the V28 vs V24 difference for M79.669?

Accepted Answer

M79.669 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 community model rewards M79.669 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's V28/V24 community RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a community payment HCC.

Question 7

What documentation supports M79.669?

Accepted Answer

Use only when laterality is truly unspecified in the medical record Consider querying for clarification if bilateral lower leg pain is present M79.669 is not a CMS-HCC payment code, so MEAT is not the payment hook. Documentation still has to support the diagnosis if you report it.

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M79.669

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M79.669 ICD-10-CM Code: Pain in unspecified lower leg

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M79.669

Is M79.669 an HCC code?

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