I connect two increasingly popular ideas in social epistemology—group knowledge and epistemic extension—both departures from mainstream epistemological tradition. In doing so, I generate a framework for conceptualizing and organizing contemporary epistemology along several core axes. This, in turn, allows me to delineate a largely unexplored frontier in group epistemology. The bulk of extant work in group epistemology can be dubbed intra-group epistemology: the study of epistemically salient happenings within groups. I delineate and attempt to motivate what I dub inter-group epistemology: (...) the study of epistemically salient happenings between groups and other subjects and entities. (shrink)