Millimeter wave access system and method for device-to-device communications (D2D) are described. A method includes registering, by one or more Citizens Broadband Radio Service (CBRS) devices (CBSDs) with a millimeter wave spectrum access system (MAS), establishing, by mobile devices, connections with a CBSD, receiving D2D communication mode capability from the mobile devices, receiving millimeter wave spectrum allocation requests for D2D communication from a number of the plurality of mobile devices, determining, by the MAS, millimeter wave spectrum allocation for the requests, sending, by the MAS and the CBSD, appropriate millimeter wave spectrum allocations to each of requesting mobile device and enabling D2D communication mode, establishing D2D communication links with other mobile devices to exchange data, monitoring idle time percentage on the D2D communication links, informing when D2D communication is not needed based on the idle time percentage, and releasing allocated millimeter wave spectrum when D2D communication is not needed.