Organizations often leverage cross-functional teams to create innovative solutions and products, yet collaboration across functional boundaries is inherently challenging. Research on small teams largely suggests that, to facilitate team creative outcomes, subgroups should integrate across functional boundaries by increasing communication. In contrast, research on larger cross-functional teams (e.g., multiteam systems) suggests that too much communication across knowledge domains can worsen team outcomes. Using a quasi-experimental design, we investigate the influence of these two different team structures on cross-functional team communication and subsequent innovation outcomes. Contrary to the prevailing recommendation for an integrated team structure in small teams, results illustrate that integrating teams, and the resultant extensive cross-functional communication, does not enhance team innovation outcomes. Rather, teams with greater functional subgroup differentiation, though exhibiting relatively less cross-functional communication, exhibit greater cross-functional synthesis. These results suggest important implications for managers of cross-functional knowledge integration work as well as the future study of cross-functional teamwork of all sizes.