This article presents the Consolidated Framework for Implementation Research (CFIR), a comprehensive framework that integrates key constructs from various implementation theories to guide the development and verification of implementation science. The CFIR is designed to help researchers understand and address the complex, multi-level, and transient nature of implementation contexts. It includes five major domains: intervention characteristics, outer setting, inner setting, characteristics of individuals involved, and the implementation process. Each domain contains specific constructs that are relevant to implementation success. The CFIR was developed through a systematic review of existing implementation theories, with a focus on identifying constructs that are consistently supported across theories. The framework includes 39 constructs, which are categorized into the five domains. These constructs are defined explicitly to ensure clarity and consistency in their application. The CFIR provides a structured approach to formative evaluations, helping researchers assess the implementation context, evaluate progress, and explain findings in research studies or quality improvement initiatives. The CFIR is a 'meta-theoretical' framework that synthesizes existing theories without specifying interrelationships or hypotheses. It offers a typology of constructs that can be used to guide theory development and verification about what works where and why across multiple contexts. The framework emphasizes the importance of considering the interaction between different constructs and their influence on implementation outcomes. It also highlights the need for consistent terminology and definitions to build a knowledge base of findings across multiple contexts. The CFIR is intended to be a flexible tool that can be adapted to various implementation settings and studies. It supports the exploration of essential factors that may be encountered during implementation through formative evaluations. The framework is expected to evolve as researchers continue to use and contribute to the knowledge base of implementation science. The CFIR provides a pragmatic structure for approaching complex, interacting, multi-level, and transient states of constructs in the real world by embracing, consolidating, and unifying key constructs from published implementation theories.This article presents the Consolidated Framework for Implementation Research (CFIR), a comprehensive framework that integrates key constructs from various implementation theories to guide the development and verification of implementation science. The CFIR is designed to help researchers understand and address the complex, multi-level, and transient nature of implementation contexts. It includes five major domains: intervention characteristics, outer setting, inner setting, characteristics of individuals involved, and the implementation process. Each domain contains specific constructs that are relevant to implementation success. The CFIR was developed through a systematic review of existing implementation theories, with a focus on identifying constructs that are consistently supported across theories. The framework includes 39 constructs, which are categorized into the five domains. These constructs are defined explicitly to ensure clarity and consistency in their application. The CFIR provides a structured approach to formative evaluations, helping researchers assess the implementation context, evaluate progress, and explain findings in research studies or quality improvement initiatives. The CFIR is a 'meta-theoretical' framework that synthesizes existing theories without specifying interrelationships or hypotheses. It offers a typology of constructs that can be used to guide theory development and verification about what works where and why across multiple contexts. The framework emphasizes the importance of considering the interaction between different constructs and their influence on implementation outcomes. It also highlights the need for consistent terminology and definitions to build a knowledge base of findings across multiple contexts. The CFIR is intended to be a flexible tool that can be adapted to various implementation settings and studies. It supports the exploration of essential factors that may be encountered during implementation through formative evaluations. The framework is expected to evolve as researchers continue to use and contribute to the knowledge base of implementation science. The CFIR provides a pragmatic structure for approaching complex, interacting, multi-level, and transient states of constructs in the real world by embracing, consolidating, and unifying key constructs from published implementation theories.