Implementation science is the scientific study of methods to promote the systematic uptake of research findings and evidence-based practices (EBPs) into routine practice, thereby improving the quality and effectiveness of health services. It differs from quality improvement (QI) and dissemination methods but shares characteristics with both. Implementation science involves mixed quantitative-qualitative designs to identify factors affecting EBP uptake across multiple levels, including patient, provider, clinic, facility, organization, and broader community and policy environments. It requires a solid theoretical foundation and interdisciplinary research teams. The need for implementation science arises from the significant time lag between research findings and their application in clinical practice, often taking 17 years to be adopted. Traditional healthcare research has focused on efficacy studies, but there is a growing recognition of the need for effectiveness trials that reflect real-world settings. However, effectiveness trials alone do not guarantee public health impact due to reliance on external resources and lack of ongoing support. Implementation science aims to develop strategies to promote EBP adoption, addressing barriers such as competing demands on providers, lack of knowledge and resources, and misalignment of research evidence with operational priorities. It involves evaluating the implementation process, including process, formative, and summative evaluations, and utilizing theories, models, and frameworks to guide data collection and analysis. Implementation science is crucial for maximizing healthcare value in resource-constrained environments and improving public health. It provides systematic principles and methods to address barriers and facilitators to system change, making it a critical component of learning healthcare systems. Hybrid effectiveness-implementation trial designs are increasingly used to assess both the effectiveness of EBPs and the impact of implementation strategies. Examples include studies on substance use disorders and pharmacotherapy for alcohol use disorders, which highlight the importance of formative evaluation and tailored implementation strategies. Overall, implementation science plays a vital role in bridging the gap between research and practice, ensuring that evidence-based interventions are effectively translated into real-world healthcare settings.Implementation science is the scientific study of methods to promote the systematic uptake of research findings and evidence-based practices (EBPs) into routine practice, thereby improving the quality and effectiveness of health services. It differs from quality improvement (QI) and dissemination methods but shares characteristics with both. Implementation science involves mixed quantitative-qualitative designs to identify factors affecting EBP uptake across multiple levels, including patient, provider, clinic, facility, organization, and broader community and policy environments. It requires a solid theoretical foundation and interdisciplinary research teams. The need for implementation science arises from the significant time lag between research findings and their application in clinical practice, often taking 17 years to be adopted. Traditional healthcare research has focused on efficacy studies, but there is a growing recognition of the need for effectiveness trials that reflect real-world settings. However, effectiveness trials alone do not guarantee public health impact due to reliance on external resources and lack of ongoing support. Implementation science aims to develop strategies to promote EBP adoption, addressing barriers such as competing demands on providers, lack of knowledge and resources, and misalignment of research evidence with operational priorities. It involves evaluating the implementation process, including process, formative, and summative evaluations, and utilizing theories, models, and frameworks to guide data collection and analysis. Implementation science is crucial for maximizing healthcare value in resource-constrained environments and improving public health. It provides systematic principles and methods to address barriers and facilitators to system change, making it a critical component of learning healthcare systems. Hybrid effectiveness-implementation trial designs are increasingly used to assess both the effectiveness of EBPs and the impact of implementation strategies. Examples include studies on substance use disorders and pharmacotherapy for alcohol use disorders, which highlight the importance of formative evaluation and tailored implementation strategies. Overall, implementation science plays a vital role in bridging the gap between research and practice, ensuring that evidence-based interventions are effectively translated into real-world healthcare settings.