This article argues that Brazil’s success in responding to the AIDS epidemic rested in the government’s pursuit of a reversal of decentralization, which entailed the government’s delegation of policy-making autonomy, funding, and discretionary fiscal transfers to the national AIDS program. AIDS bureaucrats achieved this by establishing close partnerships with social health movements and AIDS nongovernmental organizations advocating policy ideas with a historically proven track record of success while resembling similar social health movements in the past. This partnership, in turn, provided AIDS bureaucrats with the legitimacy and influenced needed for policy reform.