ICD-10 Code D75.83 – Thrombocytosis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D75.83 – Thrombocytosis
What it is
Thrombocytosis means an abnormally increased platelet count in the blood. Use this code when the record documents thrombocytosis as the diagnosis or a confirmed condition.
Clinical signs
Clinical features vary; refer to documentation. It may be found on a complete blood count and can be described as persistent or reactive thrombocytosis, depending on the cause.
When to use this code
Use D75.83 when the clinician documents thrombocytosis as an active diagnosis, including incidental or follow-up findings that are being assessed. Code it when the note clearly identifies elevated platelets without a more specific underlying condition being coded instead.
Do not use for
Do not use this code for thrombocytopenia or for a temporary platelet rise that is not documented as thrombocytosis. Check documentation if the platelet abnormality is better explained by another diagnosis.
Coding tip
Assign the code only when thrombocytosis is explicitly documented; if the cause is stated, code the underlying condition as well.