This study investigates expertise (i.e., high level of individual task performance) and self-efficacy as predictors of an individual's contribution to teamwork processes (problem analysis, goal specification) during team meetings. Multilevel, multisource data from a longitudinal field study in 22 professional software design teams reveal large within-team variability in individual contributions to teamwork processes. Expertise positively predicted a team member's contribution to meeting processes 1 year later, also when controlling for the initial level of contribution. Contrary to the hypothesis, self-efficacy was negatively related to problem analysis during team meetings.