Significant opportunities exist for the use of Unmanned Aircraft Systems in the NAS, particularly for commercial applications. In this proposed effort, we will develop a set of optimization/simulation models to support the accommodation and integration of UAS into the NAS. These optimization/simulation models will be based on previously-developed DAC algorithms which we will adapt to accommodate UAS. At the end of each Phase of the effort, these concepts and algorithms will be transferred to NASA. These models are expected to support evaluation of NextGen concepts and consequently expedite the NAS transformation, and can be used by NASA within other NASA simulation environments and technology to handle airspace management functions related to UAS. If proven successful, the concepts and algorithms to be developed through this research effort for the integration of UAS into the NAS via DAC could be used to support the FAA strategic and tactical traffic flow management. We also anticipate that the coordination of UAS operations in the NAS will require additional infrastructure and procedures to handle route coordination, airspace segregation, communication and surveillance. Thus, the work to be conducted in this effort will also provide a structure for develop of commercial tools to support UAS operators in their effort to operate in the NAS.