Which of these is required for an injury to be covered under health insurance policies with an "accidental bodily injury" definition of injury?

For an injury to be covered under health insurance policies that define injury as "accidental bodily injury," it is essential that the injury itself is accidental. This means that the injury must occur unexpectedly and unintentionally, reflecting the fundamental principle of covering unforeseen events rather than those that are planned or anticipated. The definition emphasizes the nature of the injury rather than the circumstances surrounding its occurrence.

The other options present requirements that are generally not necessary under this definition. For instance, proving reasonable care is typically not a condition for coverage in cases of accidental injuries, as insurance policies inherently assume that accidents can occur even when care is taken. Similarly, there is no stipulation that the insured must seek treatment in an emergency room for the injury to be covered; treatment can occur in various settings based on the nature of the injury. Lastly, the visibility of external signs is not a prerequisite for coverage, as internal injuries or conditions may also warrant coverage, even if they do not exhibit visible symptoms.

Thus, the correct answer is focused on the core aspect of the policy's definition, underscoring that the injury must indeed be an accident.