Do electoral institutions matter for subnational legislators’ career choices in a multi‐level polity? The paper considers this question by analyzing candidacies of sitting German State MPs for the Federal parliament (“level‐hopping attempts”), leveraging cross‐ and within‐legislature variation in electoral rules (due to the widespread adoption of mixed‐member systems in Germany's subnational parliaments). State MPs elected via list PR can be expected to be more likely to attempt level‐hopping than those elected in the single‐member districts (SMD) tier, as the former face lower re‐election rates and the latter are more directly accountable to their constituency's voters. Empirical evidence from a novel dataset of over 8000 State legislators spanning 10 Federal elections (1987–2021) confirms this hypothesis. It is also shown that the difference in behavior across tiers is more marked when State MPs run for insecure Federal candidacies than when they are offered secure candidacies. The findings suggest that subnational electoral institutions play a role in enabling or constraining legislators' progressive ambition. Moreover, they highlight a previously overlooked dimension of the “mandate divide” between MPs belonging to different electoral tiers of mixed‐member systems.