This bill establishes a comprehensive program for patient-centered research and quality improvement to address diagnostic errors. The program, housed within the Public Health Service Act, aims to assess and understand diagnostic errors , including delays, and identify strategies to eliminate common failures that lead to significant patient harm. It will also develop and disseminate evidence-based strategies and best practices for improving diagnostic quality, safety, and timeliness, ultimately reducing healthcare waste. The legislation mandates the Agency for Healthcare Research and Quality to develop a strategic plan for a patient safety reporting system , enabling patients and families to voluntarily report diagnostic errors and adverse events. It also directs the Secretary of Health and Human Services to promote the standardization and interoperability of key data elements essential for diagnostic research and improvement. Additionally, an Interagency Council on Improving Diagnosis in Health Care will be established to coordinate federal efforts, identify research gaps, and develop a strategic plan to enhance diagnostic quality across the healthcare system. The bill also authorizes appropriations for these initiatives and expands fellowships and training grants to include diagnostic safety and quality research.