D47.09 vs D89.40
D47.09 (Other mast cell neoplasms of uncertain behavior) compared with D89.40 (Mast cell activation, unspecified), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. D89.40 carries an Excludes1 note covering D47.09: “mastocytoma NOS (D47.09)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
No — do not report together. D89.40 carries an Excludes1 note covering D47.09: “other mast cell neoplasms of uncertain behavior (D47.09)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| D47.09Other mast cell neoplasms of uncertain behavior | D89.40Mast cell activation, unspecified | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | D50-D89 — Diseases of the Blood and Blood-forming Organs and Certain Disorders Involving the Immune Mechanism (D50-D89) |
| Definition | Other mast cell neoplasms of uncertain behavior is a billable ICD-10-CM diagnosis code (D47.09). | Mast cell activation, unspecified is a billable ICD-10-CM diagnosis code (D89.40). |
| Includes | Extracutaneous mastocytoma Mast cell tumor NOS Mastocytoma NOS Mastocytosis NOS | defects in the complement system immunodeficiency disorders, except human immunodeficiency virus [HIV] disease sarcoidosis Mast cell activation disorder, unspecified |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources