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

T78.121A is a billable diagnosis code used to specify a medical diagnosis of other adverse food reaction due to egg with reactivity to baked egg, initial 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.

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.

T78.121A is an initial encounter code, includes a 7th character and should be used while the patient is receiving active treatment for a condition like other adverse food reaction due to egg with reactivity to baked egg. According to ICD-10-CM Guidelines an "initial encounter" doesn't necessarily means "initial visit". The 7th character should be used when the patient is undergoing active treatment regardless if new or different providers saw the patient over the course of a treatment. The appropriate 7th character codes should also be used even if the patient delayed seeking treatment for a condition.