The management of sustainability transitions often includes action to accelerate technological change. Deployment policies are essential measures to increase the adoption of technologies and spur technological development. However, processes of technological development often follow non-linear pathways, and aligning policy and technological development is challenging. This paper links technological innovation systems (TIS) and their dynamics to the policy feedback framework based on the notion that policies shape future politics. Most significantly, the explicit consideration of TIS processes and progress allows for a more nuanced view of how policy effects turn into feedback and for assessing the co-evolution of TIS and policy over time. This framework is applied to study the case of the German Renewable Energy Act (EEG, 1999–2017). The case study provides evidence that the virtuous cycles of rapid TIS development also increase the odds of growing negative feedback based on rising policy costs, competition within sectors, and increasing technology side effects, opening up windows of opportunity for policy change. Based on these observations, this paper proposes an ideal-typical technology deployment policy life cycle model that describes how TIS, the focal policy, and their context co-evolve in a reciprocal process for the case of the EEG. The discussion sheds light on how deployment policies trigger search processes within the TIS that may encroach national borders to satisfy technology demand. Such search processes fuel political optimism. Rising policy costs and side effects, however, produce policy feedback limiting political leverage. The proposition of a model of how the linkages between policy and technology unfold over time contributes to understanding the timing of policies within sustainability transitions.