Welcome back to The Peds NP Acute Care Faculty series! This series was created and peer-edited by national leaders in acute care PNP education collaborating with one another to meet the needs of our current and future colleagues. In the push for competency-based education where faculty verify the skills of what a student can do, rather than their knowledge, our series focuses on the application of didactic content with a practical approach so that you can learn nuances of clinical skills before you reach the bedside.    This episode guides the novice pediatric provider on creations of an acute care differential diagnosis. It starts with a story about a Southerner in a snowstorm and the unfortunate car problem that resulted from an unexpected guest in the engine. A clear parallel ties the mechanic’s diagnosis with a few amateur onomatopoeias (“clunk, clunk, clunk”) with the skills needed to form illness scripts and develop differentials. A brief case study on an adolescent with acidosis introduces the idea of broad differential formation and the importance of a complete evaluation before diagnoses are eliminated. Medical decision-making is difficult, and a systematic approach to differential diagnosis formation is essential. The episode uses simple examples to help listeners apply the concepts and form a differential in real time. The discussion covers the importance of careful accrual of information, initial differential creation using a systematic approach, how to narrow your differential based on key findings of the assessment, and how to approach an open-ended differential honestly with families while avoiding cognitive bias. With the understanding that, “disease exists on a continuum that evolves and we see the patient at a snapshot in time,” the episode offers a step by step guide on how to build a differential. Classic mantras of The Peds NP are finally explained and tied to the development of your acute care differential. Every novice needs to listen to this episode before ever stepping foot in the clinical setting to be prepared for diagnostic reasoning and the process of narrowing your differential.   This episode was peer reviewed by The Peds NP faculty series peer review team. You can read about our novel and scholarly approach to peer review, review our faculty lineup, and learn more about the series, competency mapping, references, and show notes at www.thepedsnp.com. There was no financial support or conflicts of interest to report. Follow me on Instagram @thepedsnppodcast.  Email me at thepedsnp@gmail.com.  Remember that this isn’t just a podcast, you’re listening for the kids.   Authors (alphabetical):  Aimee Bucci DNP, APRN, CPNP-AC, Becky Carson, DNP, APRN, CPNP-PC/AC, & Dani Sebbens, DNP, CPNP-PC/AC   References: Balogh, E. P., Miller, B. T., Ball, J. R., Committee on Diagnostic Error in Health Care, Board on Health Care Services, Institute of Medicine, & The National Academies of Sciences, Engineering, and Medicine (Eds.). (2015). Improving Diagnosis in Health Care. National Academies Press (US). Brennan, M.M (2020). Teaching strategy 1: cultivating diagnostic decision-making with problem based learning: from most likely to least likely. Innovative Strategies in Teaching Nursing. doi: 10.1891/9780826161215 Carson, R. A., & Lyles, J. L. (2024). Cognitive Bias in an Infant with Constipation. The Journal of pediatrics, 113996. Advance online publication. https://doi.org/10.1016/j.jpeds.2024.113996 Hammond, M. E. H., Stehlik, J., Drakos, S. G., & Kfoury, A. G. (2021). Bias in Medicine: Lessons Learned and Mitigation Strategies. JACC. Basic to translational science, 6(1), 78–85. https://doi.org/10.1016/j.jacbts.2020.07.012Marshall, T. L., Rinke, M. L., Olson, A. P. J., & Brady, P. W. (2022). Diagnostic Error in Pediatrics: A Narrative Review. Pediatrics, 149(Suppl 3), e2020045948D. https://doi.org/10.1542/peds.2020-045948D Marshall, T. L., Rinke, M. L., Olson, A. P. J., & Brad