No, the employer is not required to pay for time when the employee is at a doctor's office, clinic, or hospital, even if the injury is work related. If the injury is work related, the employee may be entitled to worker's compensation or, if worker's compensation is not avaible, to sue (e.g. for lost wages, pain and suffering, medical costs)--that's his available compensation. However, he does not have to be paid when not working.