ICD-10 Code C86.40 – Blastic NK-cell lymphoma not having achieved remission (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C86.40 – Blastic NK-cell lymphoma not having achieved remission
What it is
This code identifies blastic NK-cell lymphoma that is still active and has not entered remission. Use it when the record clearly states the disease is present and remission has not been achieved.
Clinical signs
Clinical features vary; refer to documentation. Typical records may note an aggressive lymphoma with rapidly enlarging masses, skin lesions, lymph node involvement, or systemic symptoms such as fever, weight loss, or fatigue.
When to use this code
Use C86.40 when the provider documents blastic NK-cell lymphoma and specifically states it is not in remission. This applies at diagnosis, persistent disease, relapse, or ongoing active disease when remission status is clearly documented. If remission status is unclear, check documentation.
Do not use for
Do not use this code if the lymphoma is documented as in remission, history only, or if the diagnosis is uncertain. Do not assign it for other NK-cell or T-cell lymphomas unless blastic NK-cell lymphoma is specifically stated.
Coding tip
Verify the exact lymphoma type and remission status in the provider note before coding.