Phase-out is rapidly gaining traction as a central part of practical efforts to address sustainability challenges. However, the way it has been conceived of in policy debates and some academic work is problematic in that it (1) tends to be narrowly focused on substitution; (2) underexposes the bidirectional relationship between phase-outs and innovation; and (3) pays insufficient attention to political challenges. To fully reap the potential of phase-out in sustainability transitions, we call for a more integrative body of scholarship. We identify three important avenues to advance this agenda: First, shifting the unit of analysis to socio-technical systems and the reconfiguration of entire regimes will help to elucidate the multiple logics underlying phase-outs. Second, deepening insights on the timing and interaction between phase-out and innovation will unveil the potential of phase-outs in accelerating transitions. Finally, engaging with issues of power, political legitimacy, and equity is required to mitigate political challenges.