ICD-10-CM 2027
ICD-10 code for tumor mast cell
Other mast cell neoplasms of uncertain behavior
From the official ICD-10-CM alphabetic index entry “Mast cell › tumor”. Page updated September 29, 2026.
About coding tumor mast cell
The ICD-10-CM code for tumor mast cell is D47.09 (Other mast cell neoplasms of uncertain behavior).
Within D47.0, choose D47.09 (Other mast cell neoplasms of uncertain behavior) only when documentation doesn't support a more specific option: cutaneous mastocytosis (D47.01) and systemic mastocytosis (D47.02).
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 823 (Lymphoma and Non-Acute Leukemia with Other Procedures with MCC, relative weight 4.6059), DRG 824 (Lymphoma and Non-Acute Leukemia with Other Procedures with CC, relative weight 2.2515), DRG 825 (Lymphoma and Non-Acute Leukemia with Other Procedures without CC/MCC, relative weight 1.2995) and 3 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.
Common questions about tumor mast cell ICD-10 codes
What is the ICD-10 code for tumor mast cell?
- D47.09 — Other mast cell neoplasms of uncertain behavior.
Is D47.09 billable?
- Yes. D47.09 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can D47.09 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict D47.09 as a principal diagnosis.
Is D47.09 a CC or MCC?
- D47.09 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.