Many important contexts requiring teamwork, including health care, space exploration, national defense, and scientific discovery, present important challenges that cannot be addressed by a single team working independently. Instead, the complex goals these contexts present often require effectively coordinated efforts of multiple specialized teams working together as a multiteam system (MTS). For almost 2 decades, researchers have endeavored to understand the novelties and nuances for teamwork and collaboration that ensue when teams operate together as “component teams” in these interdependent systems. In this special issue on the settings of teamwork, we aim to synthesize what is known thus far regarding teamwork situated in MTS contexts and offer new directions and considerations for developing, maintaining, and sustaining effective collaboration in MTSs. Our review of extant research on MTSs reveals 7 key lessons learned regarding teamwork situated in MTSs, but also reveals that much is left to learn about the science and practice of ensuring effective multiteam functioning. We elaborate these lessons and delineate 4 major opportunities for advancing the science of MTSs as a critical embedding context for collaboration and teamwork, now and in the future.