This paper introduces a dynamic theory of ministerial appointments in coalition governments, arguing that party leaders reward MPs who fulfilled their expected roles in the prior government-opposition conflict. Using all speeches from the German Bundestag of six decades (1961–2021), we estimate MPs’ expressed positions on the government-opposition conflict dimension and assess their effect on cabinet selection. Contrary to the expectation that party leaders prefer moderate ministers to foster cooperation, we find that more loyal MPs – strong government defenders or fierce critics – are more likely to be appointed. These findings highlight how past parliamentary behavior affects future cabinet formation and suggest that ministerial appointments are shaped by partisan loyalty and role fulfillment.