ICD-10-CM 2027
ICD-10 code for hereditary alpha tryptasemia
From the official ICD-10-CM alphabetic index entry “Hereditary alpha tryptasemia (syndrome)”. Page updated September 29, 2026.
About coding hereditary alpha tryptasemia
The ICD-10-CM code for hereditary alpha tryptasemia is D89.44 (Hereditary alpha tryptasemia).
Within D89.4 (mast cell activation syndrome and related disorders), D89.44 is specifically for hereditary alpha tryptasemia. Related codes cover mast cell activation, unspecified (D89.40), monoclonal mast cell activation syndrome (D89.41), idiopathic mast cell activation syndrome (D89.42), secondary mast cell activation (D89.43) and other mast cell activation disorder (D89.49).
Use an additional code, if applicable, for: allergy status, other than to drugs and biological substances (Z91.0-) and personal history of anaphylaxis (Z87.892).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
Common questions about hereditary alpha tryptasemia ICD-10 codes
What is the ICD-10 code for hereditary alpha tryptasemia?
- D89.44 — Hereditary alpha tryptasemia.
Is D89.44 billable?
- Yes. D89.44 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can D89.44 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict D89.44 as a principal diagnosis.
Is D89.44 a CC or MCC?
- No. D89.44 is neither a CC nor an MCC under MS-DRG v44.0.