T78.129A vs T78.129D
T78.129A (Other adverse food reaction due to egg with baked egg tolerance/reactivity, unspecified, initial encounter) compared with T78.129D (Other adverse food reaction due to egg with baked egg tolerance/reactivity, unspecified, subsequent encounter), from the official CMS tabular data. T78.129A and T78.129D code the same injury at a different phase of treatment.
Can these codes be reported together?
Same injury, other encounter phase. T78.129A and T78.129D code the same injury at a different phase of treatment, set by the 7th character.
The 7th character records the type of care given at the encounter being coded (ICD-10-CM Official Guidelines, Section I.C.19.a), so one encounter takes one of these, not both.
Side by side
| T78.129AOther adverse food reaction due to egg with baked egg tolerance/reactivity, unspecified, initial encounter | T78.129DOther adverse food reaction due to egg with baked egg tolerance/reactivity, unspecified, subsequent encounter | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) |
| Definition | Other adverse food reaction due to egg with baked egg tolerance/reactivity, unspecified, initial encounter is a billable ICD-10-CM diagnosis code (T78.129A). | Other adverse food reaction due to egg with baked egg tolerance/reactivity, unspecified, subsequent encounter is a billable ICD-10-CM diagnosis code (T78.129D). |
| 7th character | The appropriate 7th character is to be added to each code from category T78 | The appropriate 7th character is to be added to each code from category T78 |
| Use additional code | code to identify the type of reaction, if applicable | code to identify the type of reaction, if applicable |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources