D89.4

ICD-10Non-billable category

Mast cell activation syndrome and related disorders

Official ICD-10-CM descriptor (FY2026)

Mast cell activation syndrome and related disorders

D89.4 is a category heading, not a billable code. CMS does not accept it on a claim; report one of the more specific codes beneath it.

Excludes1

Not coded here. An Excludes1 code should never be reported at the same time as the code above it.

  • aggressive systemic mastocytosis (C96.21)
  • congenital cutaneous mastocytosis (Q82.2)
  • (non-congenital) cutaneous mastocytosis (D47.01)
  • (indolent) systemic mastocytosis (D47.02)
  • malignant mast cell neoplasm (C96.2-)
  • malignant mastocytoma (C96.29)
  • mast cell leukemia (C94.3-)
  • mast cell sarcoma (C96.22)
  • mastocytoma NOS (D47.09)
  • other mast cell neoplasms of uncertain behavior (D47.09)
  • systemic mastocytosis associated with a clonal hematologic non-mast cell lineage disease (SM-AHNMD) (D47.02)

ICD-10-CM FY2026 defines 6 codes beneath D89.4. See the ICD-10-CM index for what this site publishes.

Related codes in D89

Where this code sits

Parent code
D89

Krasyn AI Coder

Get code suggestions automatically as you type notes. Free for 50 analyses.

Install for Chrome — free

Source

ICD-10-CM FY2026. Centers for Medicare & Medicaid Services (CMS) / National Center for Health Statistics (NCHS), “2026 ICD-10-CM Code Descriptions in Tabular Order” (icd10cm_order_2026.txt). Download the original file from cms.gov. Public domain (US Government work). Descriptors, billable flags and instructional notes on this page are reproduced from that file without modification. Krasyn adds no clinical guidance.

Get codes automatically as you write notes. Krasyn AI Coder for Chrome — free for 50 analyses.Install free →