T78.121Header code — not billable
Other adverse food reaction due to egg with reactivity to baked egg
Short description: Other adverse food reaction due to egg with rct to baked egg
- 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 T78.121?
T78.121 is an ICD-10-CM diagnosis code for Other adverse food reaction due to egg with reactivity to baked egg.
Is T78.121 a billable code?
No. T78.121 is a category/header code, not billable on its own — use one of its more specific child codes instead.
What ICD-10-CM chapter is T78.121 in?
T78.121 falls under Chapter 19: Injury, poisoning and certain other consequences of external causes.
When did T78.121 become effective?
T78.121 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to T78.121?
T78.121 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.