Is there a relationship between a party’s capacity to influence legislative decision-making and its decision to be part of a government coalition? In this study, we argue that when formal legislative rules are more conducive to actors’ policy preferences, parties have fewer incentives to join the cabinet. To test our analytical model, we analyze 68 governments and 112 cabinets in 12 presidential systems, from 1979 to 2011. Our results indicate that the decision to integrate the cabinet in presidential systems is related to the level of influence parties have on legislative policy formation in Latin American democracies.