T78.4
Non-billableOther and unspecified allergy
T78.4 is the ICD-10-CM code for Other and unspecified allergy. It is a non-billable category code — use a more specific child code such as T78.40 for billing.
S00-T88 Injury, poisoning and certain other consequences of external causes
What this means — in plain language
MedlinePlus · NIHAn allergy is a reaction by your immune system to something that does not bother most other people. People who have allergies often are sensitive to more than one thing. Substances that often cause reactions are: Pollen Dust mites Mold spores Pet dander Food Insect stings Medicines Normally, your immune system fights germs. It is your body's defense system. In most allergic reactions, however, it is responding to a…
Read more about Allergy at MedlinePlus ↗Source: U.S. National Library of Medicine (MedlinePlus). Informational only — not medical advice.
Excludes1 — not coded here
Frequently asked questions
- What is ICD-10 code T78.4?
- T78.4 is the ICD-10-CM code for "Other and unspecified allergy". It falls under S00-T88 Injury, poisoning and certain other consequences of external causes.
- Is T78.4 a billable code?
- No — T78.4 is a non-billable header code. Use a more specific child code (such as T78.40) for billing.
Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.
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