ICD-10 Code C91.41 – Hairy cell leukemia, in remission (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C91.41 – Hairy cell leukemia, in remission
What it is
C91.41 identifies hairy cell leukemia that is in remission. Use it when the diagnosis remains relevant, but the disease is not currently active.
Clinical signs
Clinical features vary; refer to documentation. Remission usually means the leukemia is no longer showing active disease on follow-up assessment.
When to use this code
Use this code when the provider documents hairy cell leukemia as “in remission,” “in complete remission,” or similar wording. It supports ongoing history and follow-up coding when the condition is not active. Check documentation if the note does not clearly state remission status.
Do not use for
Do not use C91.41 for active hairy cell leukemia or when remission is not documented. If the record only says history of leukemia without current remission status, check documentation.
Coding tip
Code the remission status exactly as documented; do not assume remission from surveillance or stable follow-up notes.