T78.40
Billable codeAllergy, unspecified
The ICD-10 code for allergy, unspecified is T78.40.
Clinical notes
Also known as
Alternate wording, synonyms, or specific conditions that fall under this code, listed to help confirm you've picked the right one.
- Allergic reaction NOS
- Hypersensitivity NOS
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •This code describes an unspecified presentation. If the medical record documents a more specific detail (e.g. laterality, type, or affected site), a more specific sibling code should be used instead — see Related codes below.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
Related codes in this category
- T78.41Arthus phenomenon
- T78.49Other allergy
- T78.40Allergy, unspecified