What obligation does an employer have to pay wages for the time spent by an employee traveling to and being seen by a medical professional as a result of a work-related injury/illness?

Both state and federal law apply in this situation.

The federal regulation interpreting the Fair Labor Standards Act provides that “[t]ime spent by an employee in waiting for and receiving medical attention on the premises or at the direction of the employer during the employee’s normal working hours on days when he is working constitutes hours worked.” (29 Code of Federal Regulations 785.43)

This means that the employer would be responsible for paying the employee wages on the day of the injury, up to the point in time the employee was scheduled to end his normal work day, since you required him to be seen by the medical professional as a result of his