FY2027 ICD-10-CM reference
D47.02: Systemic mastocytosis
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Systemic mastocytosis. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Billable code. Verified against the official FY2027 order file.
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Instructional note
Functional activity
Source: C00-D49 (chapter, inherited).
Instructional note
All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
Source: C00-D49 (chapter, inherited).
Instructional note
Morphology [Histology]
Source: C00-D49 (chapter, inherited).
Instructional note
Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
Source: C00-D49 (chapter, inherited).
Instructional note
Primary malignant neoplasms overlapping site boundaries
Source: C00-D49 (chapter, inherited).
Instructional note
A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
Source: C00-D49 (chapter, inherited).
Instructional note
Malignant neoplasm of ectopic tissue
Source: C00-D49 (chapter, inherited).
Instructional note
Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).
Source: C00-D49 (chapter, inherited).
Instructional note
Categories D37-D44, and D48 classify by site neoplasms of uncertain behavior, i.e., histologic confirmation whether the neoplasm is malignant or benign cannot be made.
Source: D37-D48 (section, inherited).
Excludes1
neoplasms of unspecified behavior (D49.-)
Source: D37-D48 (section, inherited).
Excludes1
congenital cutaneous mastocytosis (Q82.2)
Source: D47.0 (self, inherited).
Excludes1
histiocytic neoplasms of uncertain behavior (D47.Z9)
Source: D47.0 (self, inherited).
Excludes1
malignant mast cell neoplasm (C96.2-)
Source: D47.0 (self, inherited).
Instructional note
Indolent systemic mastocytosis
Source: D47.02 (self, direct).
Instructional note
Isolated bone marrow mastocytosis
Source: D47.02 (self, direct).
Instructional note
Smoldering systemic mastocytosis
Source: D47.02 (self, direct).
Instructional note
Systemic mastocytosis, with an associated hematological non-mast cell lineage disease (SM-AHNMD)
Source: D47.02 (self, direct).
Code also
, if applicable, any associated hematological non-mast cell lineage disease, such as:
Source: D47.02 (self, direct).
Code also
acute myeloid leukemia (C92.6-, C92.A-)
Source: D47.02 (self, direct).
Code also
chronic myelomonocytic leukemia (C93.1-)
Source: D47.02 (self, direct).
Code also
essential thrombocytosis (D47.3)
Source: D47.02 (self, direct).
Code also
hypereosinophilic syndrome (D72.1)
Source: D47.02 (self, direct).
Code also
myelodysplastic syndrome (D46.9)
Source: D47.02 (self, direct).
Code also
myeloproliferative syndrome (D47.1)
Source: D47.02 (self, direct).
Code also
non-Hodgkin lymphoma (C82-C85)
Source: D47.02 (self, direct).
Code also
plasma cell myeloma (C90.0-)
Source: D47.02 (self, direct).
Code also
polycythemia vera (D45)
Source: D47.02 (self, direct).
Excludes1
aggressive systemic mastocytosis (C96.21)
Source: D47.02 (self, direct).
Excludes1
mast cell leukemia (C94.3-)
Source: D47.02 (self, direct).
Compare the FY2027 additions, removals and billable-status changes
What does D47.02 mean in FY2027?
The official ICD-10-CM descriptor is Systemic mastocytosis. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is D47.02 billable in FY2027?
The FY2027 order file marks D47.02 as billable. Check the complete Tabular instructions and documentation before assigning it.
Does D47.02 map to an HCC?
D47.02 has no CMS-HCC V28 category in the CMS 2027 Initial ICD-10-CM Mappings (payment year 2027, 2026 dates of service). ESRD, RxHCC, PACE and HHS-HCC mappings are still pending verification for FY2027.
Source: CMS FY2027 ICD-10-CM order file. Read the FY2027 Official Guidelines.
Review the FY2026 April edition