A series of six full-scale subassemblages were tested to investigate dogbone and haunch retrofits for pre-Northridge steel moment connections. Tests included matched pairs of specimens, one bare steel and one including composite slab. Data were collected to evaluate the influence and behavior of the concrete slab. Results that emphasize the influence of the composite slab on connection behavior and specific comments on the slab response are presented. The presence of a composite slab corresponded to higher-achieved overall plastic rotations and higher-peak attained moments. Existing estimates of composite beam capacity overestimated the specimen strengths in positive moment. Shear stud failures were observed, raising concerns about the capacity of shear studs under severe reversed cyclic loading.