The forecasted growth of wireless services and applications is driving and being driven by regulatory, technological and economic changes that will create new technical and business models in wireless service provision and spectrum management practices. The efficient use of spectrum via Dynamic Spectrum Access (DSA) methods will be key in achieving efficient use of spectrum resources in the future. However, the use of DSA methods and the enablement of efficient spectrum sharing interactions between users of spectrum requires that they can define service level agreements (SLAs) that allow the parties in the agreement to document a common understanding of the aspects of spectrum use and the roles and responsibilities of both parties in maintaining compatible spectrum use, along with enforcement mechanisms. This paper focuses on how the use of spectrum consumption models (SCM) supports the negotiation and definition of SLAs. Spectrum consumption modeling attempts to capture spectral, spatial, and temporal consumption of spectrum of any specific transmitter, receiver, system, or collection of systems. The information contained in the SCMs enable better spectrum management practices and allows for the identification of spectrum reuse opportunities. The recent addition of a probability element to the modeling approach supports the definition of softer boundaries and the negotiation of SLAs. It allows parties to agree that rare occurrences of interference are permissible. The creation of an SLA would have parties define the SCMs of their spectrum use and iteratively exchange them until the SCMs are assessed as compatible. The SLAs would be further complemented with data indicating conditions for compliance in addition to those implied by the SCMs and agreement to the methods to assess compliance and to obtain remediation.