This article advances a novel argument about the policy output of international organizations (IOs) by highlighting the role of individual staffers. We approach them as purposive actors carrying heterogeneous ideological biases that materially shape their policy choices on the job. Pursuing this argument with an empirical focus on the International Monetary Fund (IMF), we collected individual-level information on the careers of 835 IMF “mission chiefs”—staffers with primary responsibility for a particular member state—and matched them to newly-coded data on more than 15,000 IMF-mandated policy conditions over the 1980–2016 period. Leveraging the appointment of the same mission chief to different countries throughout their career, we find that individual staffers influence the number, scope, and content of IMF conditions according to their personal ideological biases. These results contribute to our understanding of the micro-foundations behind IO output, and have implications for the accountability and legitimacy of IOs.