Background The Revised IDEA (R-IDEA) assessment tool, a validated instrument iterating on the IDEA tool developed by Baker et al., allows for residency programs to provide dependable feedback on clinical reasoning skills. It evaluates clinical documentation on admission notes utilizing four categories: interpretive summary, differential diagnosis, explanation of reasoning for lead, and alternative diagnoses. The R-IDEA tool provides more detailed anchors in each domain than the original, and a composite score of 6 or more (out of 10) signifies high-quality clinical reasoning. This study evaluates the pre- and post-intervention degrees of satisfaction, self-confidence, and ease of use of the R-IDEA tool among residents and interns during inpatient clinical rotations. Additionally, it assesses the degree of improvement in interns' clinical reasoning scores. By measuring these factors, the study aims to determine the tool’s effectiveness in enhancing clinical reasoning skills and the feedback process within an academic medical setting. Methods A single-blinded prospective cohort study with simple randomization was conducted at the ProMedica Toledo Hospital across five inpatient services (four general medicine and one ICU) over three months. The admission notes of 20 interns were evaluated by trained senior residents using the R-IDEA tool at the onset of the month-long rotation, followed by standardized feedback to the interns within the first week. A second evaluation using the R- IDEA tool at the end of the month gauged the interns' clinical reasoning improvement. A blinded faculty member reviewed residents' scoring for consistency. Satisfaction and confidence levels in delivering feedback with the R-IDEA tool were measured through pre- and post-intervention surveys of 17 senior residents and 16 interns. Results Using regression models for ordinal data, the R-IDEA scoring of 40 intern admission notes showed a significant increase (p<0.001) in the composite score from an average of 5 to 9, suggesting an improvement in the quality of clinical reasoning. Using a Likert scale, results from the intern pre- and post-R-IDEA tool survey showed significant improvement (p<0.001) in median scores for confidence and knowledge in writing interpretive summaries and creating differential diagnoses. Results from the resident surveys showed significant improvement (p<0.001) in median scores for confidence in the assessment, evaluation, and feedback process. Conclusion These findings underscore the significant enhancement in intern clinical reasoning with the R- IDEA tool. Moreover, it bolsters residents' confidence in their feedback methods. This tool can be integrated into Internal Medicine residency programs as a structured tool to augment interns' clinical reasoning effectively.