The politicization of bureaucracy is a widespread strategy to increase the political control of ministerial departments in parliamentary democracies. It is, however, largely unknown why executive politicians promote some officials rather than others to high public office. Based on a unique dataset of all senior officials in German federal ministries and agencies that held office in the period 1997-2015, this article investigates whether partisan loyalty, political craft, and managerial competencies influence the chance of promotion to the highest civil service position in Germany (state secretary). [---] Although ministers also consider candidates' political craft and selected managerial competencies, they are likely to tradeoff partisan loyalty against those qualifications. The article contributes to the literature on politicization in the public sector by comparing potential and actual office holders and by including a broad set of selection criteria, moving beyond the literature's dominating focus on partisan loyalty. The methodological approach developed in this article may well be transferred to other institutional contexts and used for comparative studies in this area.