Outlined in 21 CFR Part 820 and establishes the requirements for the quality management systems of manufacturers and suppliers of medical devices intended for the U.S. market. 

The regulation encompasses the methods and documentation for the design, testing, production, control, quality assurance, labeling, packaging, storage, and shipping of medical devices. It requires manufacturers to implement a comprehensive quality system that covers all stages of a device's lifecycle, from initial conception to delivery and post-market surveillance. 

The QSR is critical for compliance with FDA regulations and is foundational for maintaining high standards of quality and safety in medical device manufacturing. In 2024, it was combined with ISO 13485 and is now called the QMSR.