Substantial progress has been made in delivering ACTs through public health systems, but high prices have kept ACTs from those buying antimalarials in pharmacies or shops—the majority of patients in Africa. This paper reports on the delivery of highly subsidized ACTs through the private sector in Tanzania, Kenya, Cambodia, and Senegal, providing insight into how the new Affordable Medicines Facility-malaria will work. In Tanzania, the location of the only project specifically designed as an AMFm-like subsidy, uptake of ACTs increased significantly (from less than 1 to 42 percent). In Kenya, ACT uptake had increased from 15 to 42 percent 15 months after the intervention began. In Cambodia, ACT awareness increased, but supply remained irregular. In Senegal, the full range of ACT packs for different age groups was still unavailable in most private shops. Private sector subsidies can increase ACT availability but countries must take into account local malaria epidemiology and treatment-seeking behavior as well as health systems, regulatory frameworks, and consumer preferences.