ICD-10 code for malignant mast cell neoplasm

The ICD-10-CM code for malignant mast cell neoplasm is C96.20 (Malignant mast cell neoplasm, unspecified). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on C96.20.

Within C96.2, choose C96.20 (unspecified) only when documentation doesn't support a more specific option: aggressive systemic mastocytosis (C96.21), mast cell sarcoma (C96.22) and other malignant mast cell neoplasm (C96.29).

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 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC, relative weight 5.6154), DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC, relative weight 4.381), DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC, relative weight 2.7307), 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) and 6 more, in Pre-MDC and 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.