The conceptualization and enactment of the ACNP role varies across settings, potentially leading to variability in outcome achievement. A conceptual framework for evaluating the ACNP role is proposed. The framework is an adaptation of the Nursing Role Effectiveness Model which was developed to facilitate the identification and investigation of nursing-sensitive outcomes. The framework represents the complex system of interrelated factors that are present in the ACNP practice situation and that affect role effectiveness. It includes three components: (i) structure--encompassing patient, ACNP and organizational variables; (ii) process--consisting of the ACNP role components (clinician, educator, researcher and administrator) and the ways in which the role is enacted; and (iii) outcomes--including patient- and cost-related outcomes. The framework proposes specific relationships among the structure, process and outcomes components. Empirical support for the framework propositions is provided, based on a review of pertinent literature. Implications for future ACNP impact studies are discussed.