ICD-10 Code C91.92 – Lymphoid leukemia, unspecified, in relapse (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C91.92 – Lymphoid leukemia, unspecified, in relapse
What it is
C91.92 identifies lymphoid leukemia that has returned after a period of remission, but the specific lymphoid subtype is not documented. Use it when the record clearly states relapse and does not name a more specific leukemia.
Clinical signs
Clinical features vary; refer to documentation. Relapse is typically supported by evidence that leukemia has reappeared after remission, such as recurrent disease findings in the chart or pathology reports.
When to use this code
Use this code when the provider documents “lymphoid leukemia” and indicates relapse, recurrence, or return of disease, but does not specify the exact subtype. It may also fit follow-up notes that confirm active relapsed disease. If the subtype is identified, code the more specific diagnosis instead.
Do not use for
Do not use this code for leukemia in remission, history of leukemia, or newly diagnosed disease without relapse. Check documentation if the record names a specific lymphoid leukemia type or another hematologic malignancy.
Coding tip
Look for the word “relapse” or “recurrent” in the assessment, and confirm that the leukemia subtype is not documented elsewhere in the chart.