There is growing concern about the movement of individuals from private sectors to bureaucracies, yet little attention is paid to how this affects interest groups’ activities. Interest groups with connections to bureaucrats may exert less effort to provide information to policymakers (the “substitution effect”) or exert more effort (the “complement effect”). We address this question by constructing a novel dataset on career trajectories of bureaucrats in the Office of the US Trade Representative (USTR) and firms that served on USTR advisory committees during the period 1997-2017. Empirical results support the substitution effect: firms with connections to USTR bureaucrats decrease their lobbying spending and participation on advisory committees. We present suggestive evidence that the substitution effect occurs when connected bureaucrats’ ideologies are closer to the median ideal point of the agency, which makes the connected bureaucrats pivotal players. Our findings suggest that an apparent decrease in interest groups’ political activities might not imply that their influence on policymaking diminished.