Many spectrum bands are significantly fragmented, i.e. they are shared among many licensees and/or diverse service allocations that have equal rights. This poses a significant barrier to rearranging operating rights among band neighbors in ways that generate value for the parties and society at large. This paper describes how band classes (groups of licensees or other band users with common interests) and band agents (entities that act on behalf of the members of a band class) formed under regulatory auspices can address this collective action problem. Band agents would hold the right to negotiate alterations in operating rights at band boundaries, the ability to make or accept payments, and the power to oblige the operators they represent to conform to these changes; all other rights would remain vested as before. Band agents can be thought of as band managers or frequency coordinators with additional powers. Band classes are opt-out; principals designated as members of a class would have to make an explicit decision not to participate. Band classes and band agents would be subject to ex ante certification by the regulator, and the agreements that they reach with band neighbors could be submitted for yes/no review by the regulator. Such a regime could be implemented in various ways, including a band agent organizing a band class under these rules on its own initiative; the regulator converting existing entities such as frequency coordinators, SAS administrators or federal agencies to band agent status; or by auctioning of band agent rights in new allocations.