C91.02Acute lymphoblastic leukemia, in relapse

C91.02 is the ICD-10-CM diagnosis code for acute lymphoblastic leukemia, in relapse. It belongs to category C91 (lymphoid leukemia), block C81-C96 (malignant neoplasms of lymphoid, hematopoietic and related tissue) and chapter 2 (neoplasms). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within C91.0 (acute lymphoblastic leukemia [ALL]), C91.02 is specifically for acute lymphoblastic leukemia, in relapse. Related codes cover leukemia not having achieved remission (C91.00) and leukemia, in remission (C91.01).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 820 (Lymphoma and Leukemia with Major O.R. Procedures with MCC, relative weight 6.2481), DRG 821 (Lymphoma and Leukemia with Major O.R. Procedures with CC, relative weight 2.2023), DRG 822 (Lymphoma and Leukemia with Major O.R. Procedures without CC/MCC, relative weight 1.1272), DRG 834 (Acute Leukemia with MCC, relative weight 5.508), DRG 835 (Acute Leukemia with CC, relative weight 2.3031), DRG 836 (Acute Leukemia without CC/MCC, relative weight 1.1406) and 4 more, in MDC 17 (Myeloproliferative Diseases and Disorders, Poorly Differentiated Neoplasms), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 204.02 (acute lymphoid leukemia, in relapse).