T78.00XA — Anaphylactic reaction due to unspecified food, initial encounter
Is T78.00XA billable?
Yes, but T78.00XA is an unspecified code. T78.00XA is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, T78.00XA is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting T78.00XA — the more specific alternatives are listed below.
More specific alternatives
- T78.01XAAnaphylactic reaction due to peanuts, initial encounter
- T78.02XAAnaphylactic reaction due to shellfish (crustaceans), initial encounter
- T78.03XAAnaphylactic reaction due to other fish, initial encounter
- T78.04XAAnaphylactic reaction due to fruits and vegetables, initial encounter
- T78.05XAAnaphylactic reaction due to tree nuts and seeds, initial encounter
- T78.06XAAnaphylactic reaction due to food additives, initial encounter
- T78.070AAnaphylactic reaction due to milk and dairy products with tolerance to baked milk, initial encounter
- T78.080AAnaphylactic reaction due to egg with tolerance to baked egg, initial encounter
- T78.09XAAnaphylactic reaction due to other food products, initial encounter
T78.00XA at a glance
| Code | T78.00XA |
|---|---|
| Description | Anaphylactic reaction due to unspecified food, initial encounter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "A" | initial encounter |
What does the 7th character "A" mean in T78.00XA?
In T78.00XA, the 7th character A means initial encounter. The 7th character is required for T78.00XA to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does T78.00XA group to?
T78.00XA sits in MDC 21 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 915Allergic Reactions with MCCmedical
- 916Allergic Reactions without MCCmedical
As a secondary diagnosis, T78.00XA is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is T78.00XA listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T78.00, the nearest indexed parent of T78.00XA. Use them to find the family, then select the specific code.
- Shock › anaphylactic › due to food
Use additional code — inherited from Chapter 19
Report an additional code alongside T78.00XA to fully describe the condition. T78.00XA is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T78.00XA, but a patient may have both at the same time. When documentation supports it, T78.00XA and the excluded code may both be reported.
Excludes2 — not included here — inherited from T78
The conditions below are not part of T78.00XA, but a patient may have both at the same time. When documentation supports it, T78.00XA and the excluded code may both be reported.
- complications of surgical and medical care NEC (T80-T88)
Code also — inherited from T66-T78
Two codes may be needed to describe the condition fully. Whether T78.00XA is sequenced first depends on the reason for the encounter.
- , if applicable, place of occurrence, such as:
- highway rest stop (Y92.523)
- school (private) (public) (state) as the place of occurrence of the external cause (Y92.21-)
- service areas as the place of occurrence of the external cause (Y92.52-)
- single-family non-institutional (private) house as the place of occurrence of the external cause (Y92.01-)
- transport vehicle as the place of occurrence of the external cause (Y92.81-)
How long has T78.00XA existed?
T78.00XA has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.