Background The use of a restrictive formulary, with placement determined through a drug-reimbursement decision-making process, is one approach to managing drug expenditures. Objective To describe the processes in drug reimbursement decision-making systems currently used in national publicly funded outpatient prescription drug insurance plans. Methods By using the Organisation for Economic Co-operation and Development (OECD) nations as the sampling frame, a search was done in the published literature, followed by the gray literature. Collected data were verified by a system expert within the prescription drug insurance plan in each country to ensure the accuracy of key data elements across countries. Results All but one country provided at least one publicly funded prescription drug formulary. Many systems have adopted similar processes of drug reimbursement decision making. All but three systems required additional consideration of clinical evidence within the decision-making process. Transparency of recommendations varied between systems, from having no information publicly available (three systems) to all information available and accessible to the public (16 systems). Only four countries did not consider cost within the drug reimbursement decision-making process. Conclusions There were similarities in the decision-making process for drug reimbursement across the systems; however, only five countries met the highest standard of transparency, requirement of evidence, and ability to appeal. Future work should focus on examining how these processes may affect formulary listing decisions for drugs between countries.