Network oscillations in the brain are routinely recorded in the clinic and in the research lab. Here we outline a new paradigm in which network oscillations serve as treatment targets for noninvasive brain stimulation. We show how transcranial alternating current stimulation (tACS) can be used to modulate network oscillations that are impaired in disorders of the central nervous system (CNS). Using rational design, a structured process of target identification, target engagement, and target validation can be deployed to develop effective noninvasive brain stimulation paradigms for the treatment of neurological and psychiatric illnesses. We conclude by outlining how this approach could be applied to two disorders of the CNS, depression and epilepsy, for which there already exist clinical brain stimulation treatment options.