ICD-10-CM Diagnosis Code T78.121D - Other adverse food reaction due to egg with reactivity to baked egg, subsequent encounter (original) (raw)

T78.121D is a billable diagnosis code used to specify a medical diagnosis of other adverse food reaction due to egg with reactivity to baked egg, subsequent encounter. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026. The code is exempt from present on admission (POA) reporting for inpatient admissions to general acute care hospitals.

This code describes a circumstance which influences the patient's health status but not a current illness or injury. The code is unacceptable as a principal diagnosis.

T78.121D is a subsequent encounter code, includes a 7th character and should be used after the patient has completed active treatment for a condition like other adverse food reaction due to egg with reactivity to baked egg. According to ICD-10-CM Guidelines a "subsequent encounter" occurs when the patient is receiving routine care for the condition during the healing or recovery phase of treatment. Subsequent diagnosis codes are appropriate during the recovery phase, no matter how many times the patient has seen the provider for this condition. If the provider needs to adjust the patient's care plan due to a setback or other complication, the encounter becomes active again.