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ICD-10-CM 2027

ICD-10 code for activation

Choose a code from the options below based on the documentation.

From the official ICD-10-CM alphabetic index entry “Activation”. Page updated September 29, 2026.

About coding activation

The official ICD-10-CM index doesn't give a single default code for activation; the code depends on the details below.

More specific activation codes (official index)

  • mast cell (disorder) (syndrome) D89.40 — Mast cell activation, unspecified
  • idiopathic D89.42 — Idiopathic mast cell activation syndrome
  • monoclonal D89.41 — Monoclonal mast cell activation syndrome
  • secondary D89.43 — Secondary mast cell activation
  • specified type NEC D89.49 — Other mast cell activation disorder

Common questions about activation ICD-10 codes

What is the ICD-10 code for mast cell activation?

D89.40 — Mast cell activation, unspecified.