Purpose Emerging clinical conditions often outpace undergraduate medical curricula, leaving learners underprepared for clinical practice. To address this gap, we developed LEARN (Long COVID Education for Assessment, Recognition, and Navigation), a competency-based curriculum designed to improve learner preparedness and confidence using Long COVID as a model for teaching complex, evolving diseases. Methods Curriculum development was guided by a national needs assessment of medical students that identified educational priorities and preferred learning strategies. LEARN was designed as a modular, asynchronous, case-based curriculum with interactive learning activities. Forty medical students completed two complementary Long COVID learning modules (Pressbook and Articulate 360). Educational outcomes were evaluated using pre- and post-module surveys assessing confidence across five competency domains, perceived educational value, anticipated impact on clinical practice, and learner preferences. Results Ninety percent of participants reported no prior formal education in Long COVID, highlighting a substantial educational gap. Following the curriculum, learners demonstrated significant improvements in confidence across all five competency domains, regardless of module format. Seventy-five percent reported they were likely or very likely to change their future clinical approach to Long COVID patients. Both formats were highly rated, with 70% preferring the interactive Articulate 360 module because of its brevity, interactivity, and visual design. Conclusion LEARN demonstrates an effective approach to preparing medical students for emerging clinical conditions. A learner-informed needs assessment, combined with competency-based curriculum design and educational evaluation, produced meaningful gains in learner confidence and preparedness. This framework offers a scalable model for rapidly developing curricula that respond to evolving healthcare needs.