T78.4

ICD-10Non-billable category

Other and unspecified allergy

Official ICD-10-CM descriptor (FY2026)

Other and unspecified allergy

T78.4 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.

  • specified types of allergic reaction such as:
  • allergic diarrhea (K52.29)
  • allergic gastroenteritis and colitis (K52.29)
  • dermatitis (L23-L25, L27.-)
  • food protein-induced enterocolitis syndrome (K52.21)
  • food protein-induced enteropathy (K52.22)
  • hay fever (J30.1)

ICD-10-CM FY2026 defines 3 codes beneath T78.4. See the ICD-10-CM index for what this site publishes.

Related codes in T78

Where this code sits

Parent code
T78

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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.

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