Significance Activation of G protein-coupled receptors (GPCRs) initiates conformational shifts that trigger interaction with a specific G-protein subtype from a structurally homologous set. A major unsolved problem is the mechanism by which this selectivity is achieved. Structures of GPCR–G protein complexes so far fail to reveal the origin of selectivity because they all involve one G-protein subtype (G _s ). In this work, we report a structural model of the activated GPCR rhodopsin in complex with another G-protein subtype (G _i ) derived from intermolecular distance mapping with DEER-EPR and refinement with modeling. Comparison of the model with structures of complexes involving G _s reveals distinct GPCR–G protein-binding modes, the differences of which suggest key features of the structural selectivity filter.