Problem: Diagnositic reasoning is an essential skill of the nurse practitioner (NP). The Information Processing (IPM) and Hermeneutics Models (HM) of diagnostic reasoning are used by NPs to accurately diagnose patients. NPs use diagnostic reasoning models differently as they develop from novice to expert. An appraisal of the skill acquisition of novice or student NPs, in diagnostic reasoning skills, and the outcome of making accurate clinical diagnoses, has not been assessed. This lack of understanding of how students develop these essential skills and how successful they are in accurately diagnosing patients leads us to question the current educational instruction and clinical evaluation methods. Purpose: The purpose of this capstone project was to develop an educational program, based on both models of diagnostic reasoning, and examine the students’ accuracy in diagnosis. The rationale for the project is that skill acquisition in diagnostic reasoning is an essential skill of the NP. Goal: The goal of the project was to successfully implement and educational program for novice FNP students as they develop their diagnostic reasoning skills, examine which skills they use, and assess the students’ accuracy in diagnosis. Objectives: First, describe the composite and mean demographic characteristics of the sample of convenience of FNP students. Second, explain the androgogical method currently used to educate FNP students in the IPM of diagnostic reasoning. Third, determine the pre-intervention diagnostic reasoning skills used by the FNP student and the accuracy of diagnosis using patient vignettes. Fourth, develop and administer the intervention of interest of androgogical instruction method of the HM of diagnostic reasoning. Fifth, administer the post-intervention to determine the diagnostic reasoning skills used by the FNP student and the accuracy of diagnosis using patient vignettes. Sixth, evaluate the change in diagnostic accuracy and skills used from diagnostic reasoning models. Plan: Phase One: Conduct a literature review/needs assessment using a published evidence based critique template. Phase Two: Design a teaching module for the intervention of interest, the HM of diagnostic reasoning. Phase Three: Obtain IRB approvals from Rocky Mountain University of Health Professions and Regis University. Implement project. Phase Four: Evaluate the change in diagnostic accuracy and the reasoning skills of the students utilizing the Nurse Practitioner Performance Tool (NPPT), several anchor questions in Likert scale format, and one open-ended question related to the development of the students’ reasoning skills. Outcomes and Results: Project results show that after the educational intervention the post test scores were higher than the pre-test scores. Additionally, participants used skills from both models of reasoning in diagnosing patients on NPPT. Themes from the lived experience of learning diagnostic reasoning were also discovered.