Several key aspects of coordination such as teamwork, roles, and communication, are enabled and driven by, and even largely defined by, various systems of regulation. One key feature of all these elements in human coordination is their dynamic nature. We have developed a framework to provide a dynamic regulatory system for supporting coordination in human-robot teamwork. This framework supports the definition and functions of roles within teams, as well as the creation of subteams and the roles within them. It also serves to regulate communications in support of coordination. We have demonstrated our system with a team of two humans and five robots performing advanced coordination while trying to apprehend an intruder hiding on a cluttered pier. This work lays the foundation for human-robot coordination based on dynamic regulation.