T78.120D — Other adverse food reaction due to egg with tolerance to baked egg, subsequent encounter
Is T78.120D billable?
Yes — T78.120D is billable for FY2027. T78.120D is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. T78.120D may be submitted for encounters from October 1, 2026 through September 30, 2027.
T78.120D at a glance
| Code | T78.120D |
|---|---|
| Description | Other adverse food reaction due to egg with tolerance to baked egg, subsequent encounter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "D" | subsequent encounter |
What does the 7th character "D" mean in T78.120D?
In T78.120D, the 7th character D means subsequent encounter. The 7th character is required for T78.120D to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
What Medicare edits apply to T78.120D?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name T78.120D directly.
CMS will reject this code as the principal diagnosis on an inpatient claim. It describes something other than the condition chiefly responsible for the admission.
Which MS-DRGs does T78.120D group to?
T78.120D sits in MDC 23 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.
- 949Aftercare with CC/MCCmedical
- 950Aftercare without CC/MCCmedical
How is T78.120D listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T78.120, the nearest indexed parent of T78.120D. Use them to find the family, then select the specific code.
- Allergy, allergic › eggs › adverse reaction NEC › with › tolerance to baked egg (reaction) (to)
Excludes1 — never code together
The conditions below can never be reported together with T78.120D on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- Other adverse food reaction due to egg with reactivity to baked egg (T78.121)
Excludes1 — never code together — inherited from T78.1
The conditions below can never be reported together with T78.120D on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Excludes1 — never code together — inherited from T78.120
The conditions below can never be reported together with T78.120D on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- Other adverse food reaction due to egg with reactivity to baked egg (T78.121)
Use additional code — inherited from Chapter 19
Report an additional code alongside T78.120D to fully describe the condition. T78.120D is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Use additional code — inherited from T78.1
Report an additional code alongside T78.120D to fully describe the condition. T78.120D is sequenced first.
- code to identify the type of reaction, if applicable
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T78.120D, but a patient may have both at the same time. When documentation supports it, T78.120D and the excluded code may both be reported.
Excludes2 — not included here — inherited from T78
The conditions below are not part of T78.120D, but a patient may have both at the same time. When documentation supports it, T78.120D and the excluded code may both be reported.
- complications of surgical and medical care NEC (T80-T88)
Excludes2 — not included here — inherited from T78.1
The conditions below are not part of T78.120D, but a patient may have both at the same time. When documentation supports it, T78.120D and the excluded code may both be reported.
Code also — inherited from T66-T78
Two codes may be needed to describe the condition fully. Whether T78.120D 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 T78.120D existed?
T78.120D first appears in FY2026.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.