Unlike prescription drugs, medical devices are reviewed by the US Food and Drug Administration (FDA) using 2 alternative regulatory standards: (1) premarket approval (PMA), which requires clinical testing and inspections; or (2) the 510(k) process, which requires that the device be similar to a device already marketed (predicate device). The second standard is intended for devices that the FDA deems to involve low or moderate risk.We analyzed the FDA's high-risk List of Device Recalls from 2005 through 2009. Using FDA data, we determined whether the recalled devices were approved by the more rigorous (PMA) process, the 510(k) process, or were exempt from FDA review.There were 113 recalls from 2005 through 2009 that the FDA determined could cause serious health problems or death. Only 21 of the 113 devices had been approved through the PMA process (19%). Eighty were cleared through the 510(k) process (71%), and an additional 8 were exempt from any FDA regulation (7%). Cardiovascular devices comprised the largest recall category, with 35 of the high-risk recalls (31%); two-thirds were cleared by the 510(k) process (66%; n = 23). Fifty-one percent of the high-risk recalls were in 5 other device categories: general hospital, anesthesiology, clinical chemistry, neurology, or ophthalmology.Most medical devices recalled for life-threatening or very serious hazards were originally cleared for market using the less stringent 510(k) process or were considered so low risk that they were exempt from review (78%). These findings suggest that reform of the regulatory process is needed to ensure the safety of medical devices.