Team-based care has been identified as an important element of effective primary care practice. While there is a growing body of literature supporting the value of team-based care, research on best practices in team-based care has suffered from the lack of a widely accepted framework with common definitions. We used qualitative interviews to explore healthcare administrators' perspectives regarding team-based care descriptions, their decisions regarding composition of a team, and how they identify characteristics of a well-functioning team. Interviewees discussed six broad themes: (1) definitions of team-based care, (2) team structure and roles, (3) team goals, (4) monitoring team effectiveness, (5) challenges to implementing team-based care, and (6) the influence of healthcare policy on team-based care. The study findings can be used to identify further ways to assess the notion of "teamness."