2027 ICD-10-CM Diagnosis Code D47.02Systemic mastocytosis

ICD-10-CM Codes›C00–D49›D37-D48›D47

ICD-10-CM D47.02
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

D47.02 is a billable ICD-10-CM diagnosis code for systemic mastocytosis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 820 through 825, 840 through 842. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 27 closely related codes. Coders also document this condition as indolent systemic mastocytosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neoplasms of unspecified nature or uncertain behavior.

D47.02 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 21 for payment year 2027.

Code Identity

ICD-10-CM Code
D47.02
Billable Status
Yes — Valid for Submission
Code Describes
Systemic mastocytosis
Short Description
Systemic mastocytosis
Same as the full description in the CMS dataset.
Parent Code
D47.0
Mast cell neoplasms of uncertain behavior

Code Classification

ChapterC00–D49Neoplasms
SectionD37-D48Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes
CategoryD47Other neoplasms of uncertain behavior of lymphoid, hematopoietic and related tissue
This CodeD47.02Systemic mastocytosis

Medicare Risk Adjustment (HCC)Billing

D47.02 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
no payment category in the model that pays 100% of MA risk scores
Prior Model (CMS-HCC V24)
Not mapped under V24
this diagnosis newly risk-adjusts under the V28 model
Part D (RxHCC)
RxHCC 21 — Lymphomas and Other Hematologic Cancers
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Indolent systemic mastocytosis
  • Isolated bone marrow mastocytosis
  • Malignant mastocytosis
  • Smoldering systemic mastocytosis
  • Systemic mast cell disease
  • Systemic mastocytosis with associated clonal hematological non-mast cell lineage disease

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to D47.02: its own notes plus those printed at D47.0, block D37-D48, and Chapter 2. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Indolent systemic mastocytosis
  • Isolated bone marrow mastocytosis
  • Smoldering systemic mastocytosis
  • Systemic mastocytosis, with an associated hematological non-mast cell lineage disease (SM-AHNMD)

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

On D47.02 itself
  • aggressive systemic mastocytosis (C96.21)
  • mast cell leukemia (C94.3-)
From D47.0 Mast cell neoplasms of uncertain behavior applies to 3 codes
  • congenital cutaneous mastocytosis (Q82.2)
  • histiocytic neoplasms of uncertain behavior (D47.Z9)
  • malignant mast cell neoplasm (C96.2-)
From Block D37-D48 Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes applies to 137 codes
  • neoplasms of unspecified behavior (D49.-)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

  • if applicable, any associated hematological non-mast cell lineage disease, such as:
  • acute myeloid leukemia (C92.6-, C92.A-)
  • chronic myelomonocytic leukemia (C93.1-)
  • essential thrombocytosis (D47.3)
  • hypereosinophilic syndrome (D72.1)
  • myelodysplastic syndrome (D46.9)
  • myeloproliferative syndrome (D47.1)
  • non-Hodgkin lymphoma (C82-C85)
  • plasma cell myeloma (C90.0-)
  • polycythemia vera (D45)

Notes

General instructions on how these codes are used.

From Block D37-D48 Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes applies to 137 codes
  • 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.
From Chapter 2 (C00-D49) Neoplasms applies to 1,730 codes
  • Functional activity
  • 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.
  • Morphology [Histology]
  • 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.
  • Primary malignant neoplasms overlapping site boundaries
  • 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.
  • Malignant neoplasm of ectopic tissue
  • 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: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name D47.02, its category, or a range that includes it.

Excludes1 4

These codes carry an Excludes1 note naming D47.02: they are not reported together with it, unless the two conditions are unrelated.

  • C96.2 Malignant mast cell neoplasm
    indolent mastocytosis (D47.02)
  • D89.4 Mast cell activation syndrome and related disorders
    (indolent) systemic mastocytosis (D47.02)
  • D89.4 Mast cell activation syndrome and related disorders
    systemic mastocytosis associated with a clonal hematologic non-mast cell lineage disease (SM-AHNMD) (D47.02)
  • Q82.2 Congenital cutaneous mastocytosis
    systemic mastocytosis (D47.02)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO072
Neoplasms of unspecified nature or uncertain behavior
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Mastocytosis, Systemic

    a group of disorders caused by the abnormal proliferation of mast cells in a variety of extracutaneous tissues including bone marrow, liver, spleen, lymph nodes, and gastrointestinal tract. systemic mastocytosis is commonly seen in adults. these diseases are categorized on the basis of clinical features, pathologic findings, and prognosis.

Patient EducationClinical

Systemic mastocytosis

Systemic mastocytosis is a blood disorder that can affect many different body systems. Individuals with the condition can develop signs and symptoms at any age, but it usually appears after adolescence.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert D47.02 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
238.5 Mastocytoma NOS
Approximate The match is approximate rather than exact.

Code History & ChangesHistory

Replacement D47.02 replaces the following previously assigned code(s):

  • D47.0 - Histiocytic and mast cell tumors of uncertain behavior
  • D47.0 - Mast cell neoplasms of uncertain behavior
FY 2019AddedAdded to the ICD-10-CM code setEffective October 1, 2018.
FY 2020–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About D47.02Overview

What is the ICD-10 code for systemic mastocytosis?

The ICD-10-CM code for systemic mastocytosis is D47.02 (sometimes written as D4702). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is D47.02 (Mast cell neoplasms of uncertain behavior) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report systemic mastocytosis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does D47.02 group to?

When systemic mastocytosis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 841, 821, 822, 825, 842, 824, 840, 820, 823, with relative weights from 0.9948 to 6.2454 depending on complications. Higher weights mean higher Medicare reimbursement.

Is D47.02 a CC or MCC?

CMS lists D47.02 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 27 closely related codes in its exclusion list.

Can D47.02 be reported with C96.21?

Not as a rule. The Excludes1 note on D47.02 lists "aggressive systemic mastocytosis (C96.21)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does D47.02 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage: D47.02 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 21 (Lymphomas and Other Hematologic Cancers).