This paper offers a novel theoretical framework to understand feminists’ mobilization to secure but also defend legal abortion in Latin America. Laws liberalizing women’s access to abortion rarely pass without significant negotiation, as proponents and opponents must agree on how permissive or restrictive the new regime should be. Conservative actors will not just seek concessions in the legislative phase. In the aftermath, they will seek the most restrictive interpretation of the law possible or try to revert it. While scholars have studied the congressional negotiations and their aftermath separately, this paper links both stages. We argue that the types of concessions feminists make in the negotiation phase directly affect their strategies in the aftermath. We differentiate two types of concessions: on the one hand, strategic sacrifices in the adoption phase allow feminists to play offense to ensure access in the aftermath. On the other hand, acceptable conditions that in the aftermath force feminists onto the defensive, as they are caught unaware of far-reaching implications. We develop this theory through the in-depth case analysis of abortion legalization in Chile and Uruguay, offering new empirical insights into the introduction and evolution of obstacles to abortion rights.