Legislative committees rely on the expertise and experience of their members, but instability in committee systems threatens the enhancements in productivity associated with specialization. This can occur in two ways, both of which are more common in state legislative committees than they are in Congress. First, membership retention on committees is generally lower, even after accounting for differing levels of legislative turnover across legislatures. Second, many state legislative committee systems undergo reorganization between sessions, changing the policy jurisdictions, and, therefore, the applicability of members' previously developed expertise. In this article, I examine the consequences of these two sources of committee instability on legislative output in 14 state legislatures. I find that both membership retention and jurisdictional reorganization significantly affect the number of bills processed through committees and the number of bills ultimately enacted. These linkages are also conditioned on several committee and institutional factors, particularly legislative turnover. Last, I find a weaker but discernible effect of membership retention on committees' propensity to perform their gatekeeping role.