Sufficient public healthcare centers are a must to ensure that every inhabitant has sufficient access to healthcare services. This present study aims to evaluate the adequacy of public healthcare centers in Yogyakarta City. Agent-based modeling and simulation (ABMS), capable of modeling heterogeneous individuals, the various capacity of the public healthcare centers, and the spatial aspect of the model, was used to simulate the load and unmet demand of the public healthcare centers. The empirical data to parameterize the simulation model were collected from an empirical survey and historical records. The simulation model can reproduce the existing load at the public healthcare centers of Jetis, Ngampilan, and Danurejan I with a non-significant difference. Base scenario simulating individuals selecting the public healthcare center in their respective districts results in the average annual load of 2387 cases and the unmet demand of 82 cases, indicating insufficient capacity, thus implying the need to expand the capacity. Selecting the nearest public healthcare center rather than the one in the respective district results in a shorter traveled distance and less unmet demand but creates an imbalance load among the centers. The trade-off between the load and traveled distance implies the necessity to consider location as well as involved stakeholders, i.e., individuals and the public healthcare centers in planning the future establishment of the public healthcare centers.