RESUMEN
Success in the implementation of evidence-based interventions (EBIs) in different settings has had variable success. Implementation research offers the approach needed to understand the variability of health outcomes from implementation strategies in different settings and why interventions were successful in some countries and failed in others. When mastered and embedded into a policy and implementation framework, the application of implementation research by countries can provide policy-makers and implementers with the knowledge necessary to work towards universal health coverage (UHC) with the effectiveness, efficiency, sustainability, and fidelity needed to achieve sustainable positive health outcomes for all. To achieve this goal however, work is needed by the communities of research producers and consumers to create more clarity on implementation research methodologies and to build capacity to apply them as a critical tool for countries on their path to achieving UHC.