ICD-10 Code C91.61 – Prolymphocytic leukemia of T-cell type, in remission (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C91.61 – Prolymphocytic leukemia of T-cell type, in remission
What it is
This code identifies a history of T-cell prolymphocytic leukemia that is currently in remission. Use it when the condition is still clinically relevant, but active disease is not documented.
Clinical signs
Clinical features vary; refer to documentation. Standard references describe a mature T-cell leukemia that may present with lymphocytosis, lymphadenopathy, splenomegaly, or skin involvement when active.
When to use this code
Use C91.61 when the provider documents T-cell prolymphocytic leukemia as in remission, controlled, or not currently active. This supports coding for follow-up care, surveillance, or ongoing hematology review. If remission is not stated, check the record before assigning this code.
Do not use for
Do not use this code for active T-cell prolymphocytic leukemia or for unspecified leukemia types. If the documentation only says “history of leukemia” without remission status, check documentation.
Coding tip
Code remission only when the provider clearly documents it; otherwise, query or verify the current disease status.