T78.40XSBillable
Allergy, unspecified, sequela
- Chapter
- 19. Injury, poisoning and certain other consequences of external causes
- Category
- T78
- Effective date
- October 1, 2026
Related codes in category T78
T78Adverse effects, not elsewhere classifiedT78.0Anaphylactic reaction due to foodT78.00Anaphylactic reaction due to unspecified foodT78.00XAAnaphylactic reaction due to unspecified food, init encntrYesT78.00XDAnaphylactic reaction due to unspecified food, subs encntrYesT78.00XSAnaphylactic reaction due to unspecified food, sequelaYesT78.01Anaphylactic reaction due to peanutsT78.01XAAnaphylactic reaction due to peanuts, initial encounterYesT78.01XDAnaphylactic reaction due to peanuts, subsequent encounterYesT78.01XSAnaphylactic reaction due to peanuts, sequelaYesT78.02Anaphylactic reaction due to shellfish (crustaceans)T78.02XAAnaphylactic reaction due to shellfish (crustaceans), initYes
Frequently asked questions
What is ICD-10 code T78.40XS?
T78.40XS is an ICD-10-CM diagnosis code for Allergy, unspecified, sequela.
Is T78.40XS a billable code?
Yes. T78.40XS is billable and specific enough to be used on a claim.
What ICD-10-CM chapter is T78.40XS in?
T78.40XS falls under Chapter 19: Injury, poisoning and certain other consequences of external causes.
When did T78.40XS become effective?
T78.40XS has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to T78.40XS?
T78.40XS belongs to category T78, which includes 12 other codes — see the related codes list on this page.
ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.