Question 1

What is ICD-10 code D75.838?

Accepted Answer

D75.838 is the ICD-10-CM diagnosis code for Other thrombocytosis. This code describes an abnormally high platelet count in the blood that doesn't fit into other specific categories of thrombocytosis. Elevated platelets can increase the risk of blood clots and may indicate an underlying condition that needs investigation. D75.838 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. D75.838 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 D75.838 an HCC code?

Accepted Answer

No. D75.838 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 D75.838 billable?

Accepted Answer

Yes. D75.838 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. D75.838 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 D75.838?

Accepted Answer

D75.838 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 D75.838 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 D75.838?

Accepted Answer

Use this code only after ruling out primary thrombocytosis (essential thrombocythemia) and secondary causes like malignancy, inflammation, or medication-induced thrombocytosis, as those have more specific codes Verify the platelet count value in the lab results and ensure the physician has documented this as thrombocytosis rather than a transient elevation, as some labs may show temporary increases

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D75.838

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D75.838 ICD-10-CM Code: Other thrombocytosis

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D75.838

Is D75.838 an HCC code?

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Work D75.838 in HCC Buddy