Methods and apparatus for spectrum coordination are described. A method of spectrum coordination includes a spectrum coordinator receiving a request for shared spectrum from a CRS that the spectrum coordinator supports. The request includes at least one minimum protection requirement. The spectrum coordinator determines protection criteria for the CRS based on the at least one minimum protection requirement received from the CRS. The spectrum coordinator sends the protection criteria for the CRS to a geo-location database for use in assigning shared spectrum to other CRSs that the spectrum coordinator does not support.