Distributed radio communications systems supporting coordination of distribution of shared spectrum from multiple service providers to remote units to be distributed to subscriber devices are disclosed. In examples, the distributed communications system includes a routing circuit that is configured to receive downlink communications signals from signal sources of respective multiple service providers and route the downlink communications signals to a plurality of remote units. The remote unit is configured to distribute the received downlink communications signals for the multiple service providers to subscriber devices such that the distributed communications system supports multiple service providers. The distributed communications system also includes a spectrum usage coordination circuit configured to coordinate the usage of spectrum between the remote units in the distributed communications system. The spectrum usage coordination circuit is configured selectively decide which channels of the shared spectrum are to be routed to specific remote units based on shared spectrum input information.