Effective hospital capacity planning can not only significantly enhance the capability and effectiveness of the treatment provided to patients during a bioterrorist attack but can also provide critical information. While a lot of work has been done to model hospital capacity estimates for natural disasters the same cannot be said for manmade biological disasters like anthrax or smallpox. In this paper, we develop a generic simulation model of hospital capacity planning during a bioterrorist attack. We model both cases in which the occurrence of the attack and the type of agent used are known as well as when they are not known. The model is also unique in developing a feedback loop to alert emergency management officials about the occurrence and type of an attack. Our results are able to pinpoint the characteristics of the hospitals that are most relevant at various stages of exposure and provide policy recommendations.