The timely examination is important for the outpatients to be properly diagnosed or treated. Hospital managers are under high pressure to make advance appointments for different types of outpatients to reach their waiting time target. To deal with this problem, this paper proposes a Markov Decision Process (MDP) model for scheduling the outpatients with one examination and two types of outpatients considered. The waiting time targets and rewards from accepting the outpatients of two types are different. The objective is to maximize the expected revenue. Extensive numerical experiments are used to estimate the properties of optimal policy for each type of patient. Sensitivity analysis is performed to investigate the effect of the parameters on the optimal policy and criterion.