T78.4
Header — not billableOther and unspecified allergy
The ICD-10 code for other and unspecified allergy is T78.4.
T78.4 is a non-billable header code. It groups related conditions but cannot be used on its own for reimbursement — select one of the 3 more specific codes below.
Clinical notes
Excludes1 (not coded here)
An Excludes1 note is a pure exclusion: the excluded condition and this code should never be reported together, because the two conditions cannot occur at the same time (e.g. a congenital form vs. an acquired form of the same disease).
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •This is a non-billable header code. Documentation must support a more specific child code before this diagnosis can be reported on a claim.
- •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.
- •Confirm the excluded condition(s) listed above are not also present — Excludes1 conditions cannot be coded together with this one.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
Child codes under T78.4
Related codes in this category
- T78.0Anaphylactic reaction due to foodnon-billable header
- T78.1Other adverse food reactions, not elsewhere classifiednon-billable header
- T78.2Anaphylactic shock, unspecified
- T78.3Angioneurotic edema
- T78.8Other adverse effects, not elsewhere classified
- T78.4Other and unspecified allergynon-billable header