Today, all countries globally, including Iran, face the challenge of spreading the COVID-19 disease. Given the limited capacity of the health care system and the risk of a recurrence of demand for testing and intensive care units (ICU), some countries may again experience fluctuating behaviors or the return of viral pandemics. Various reasons are resulting in this emerging virus in the world. Apart from the tendency to cause severe disease with a higher death rate than previous coronavirus diseases, it can spread so quickly. This study aimed to reach an optimal capacity allocation in the health care centers by intervening in government decisions and public holidays in Iran on disease control. This research is the first to analyze and develop a healthcare capacity allocation strategy by considering the mutual effects of disease outbreaks and government actions as decision aiding tools via a hybrid simulation–optimization framework. Also, we calibrate the developed hybrid simulation–optimization model for Iran on the improved SEIR framework to generate reliable outputs. The simulation results show that it is necessary to allocate some part of the health capacity to the mild symptomatic patients.