The purpose of this paper was to describe evidenced-based interventions as implemented by advanced practice nurses (APNs) conducting intervention research with a vulnerable population of blood and marrow transplant patients. In addition, each of the 6 core competencies of the APN role identified by Hamric are outlined and applied using a patient case study. These competencies are the following: direct clinical practice, expert coaching and advice, consultation, research skills, clinical and professional leadership, collaboration, and ethical decision making. This article chronicles a typical patient's journey through a post-hospital discharge nursing research study involving APNs as "intervention nurses" and discusses the various aspects of the APN core competencies throughout the process.