The described technology is generally directed towards adaptive spectrum as a service, in which spectrum can be dynamically allocated to adapt to demand for wireless capacity. The demand for wireless capacity can be based on monitoring system state, and/or proactively predicted based on other system state such as time of day. Reallocated spectrum can be monitored for performance, to converge spectrum allocation to a more optimal state. Allocated spectrum can be relocated, increased or decreased, including by the use of citizens band radio service spectrum or other spectrum. Currently allocated spectrum can be adapted into modified allocated spectrum by an application program (xApp) coupled to a radio access network intelligent controller (RIC), a citizens broadband radio service device, a domain proxy service, and/or a user device.