In 1998, the OAS member states agreed to and designed a multilateral evaluation mechanism that would make periodic recommendations to OAS member states on improving their capacity to control drug trafficking and abuse, and enhance multilateral cooperation. The Heads of State and of Government of the Americas turned the concept of multilateral evaluation into a mandate, declaring in the Plan of Action that their countries would undertake the following specific actions:

"Continue to develop their national and multilateral efforts in order to achieve full application of the Anti-Drug Strategy in the Hemisphere, and will strengthen this alliance based on the principles of respect for the sovereignty and territorial jurisdiction of the States, reciprocity, shared responsibility and an integrated, balanced approach in conformity with their domestic laws;

With the intention of strengthening mutual confidence, dialogue and hemispheric cooperation and on the basis of the aforementioned principles, develop, within the framework of the Inter-American Drug Abuse Control Commission (CICAD-OAS), a singular and objective process of multilateral governmental evaluation in order to monitor the progress of their individual and collective efforts in the Hemisphere and of all the countries participating in the Summit, in dealing with the diverse manifestations of the problem."

Based on these mandates and in order to execute them, the twenty-third regular session of CICAD (May 1998) formed an Inter-Governmental Working Group on the Multilateral Evaluation Mechanism (IWG-MEM). Headed by Canada and Chile to design the mechanism, the MEM was set to begin in 1999.

As the only multilateral evaluation of its kind in the world, the MEM highlights the strengths and weaknesses of OAS member states in its country reports, and encourages national dialogue among policymakers. The MEM also publishes a hemispheric report, which reflects the reality of member states in the Hemisphere as a whole regarding the drug problem, outlining clearly the challenges encountered, the strengths and the collective progress in implementing drug policies. Based on the CICAD Hemispheric Drug Strategy and the Plan of Action, the reports focus on the following thematic areas: institutional strengthening, demand reduction, supply reduction, control measures, and international cooperation.

During the sixty-second regular session (December 13-15, 2017), the CICAD Commissioners approved the Evaluation Questionnaire, Evaluator's Manual, Procedural Manual, and Calendar of Activities, for the seventh evaluation round. This round began in January 2018 with the submission of the MEM Evaluation Questionnaire to each OAS member states’ National Coordinating Entity (NCE), followed by the publication of the national evaluation reports on drug policies in July 2019.