reviewing in 2011. Premarket notification (510(k), PMN) Section 510(k) of the Federal Food, Drug, and Cosmetic Act requires those device manufacturers who must register to notify FDA, at least 90 days in advance, of their intent to market a medical device. This is known as premarket notification, PMN, or 510(k). It allows FDA to determine whether the device is equivalent to a device already placed into one of the three classification categories. Thus, "new" devices (not in commercial distribution prior to May 28, 1976) that have not been classified can be properly identified. Any device that reaches market via a 510(k) notification must be "substantially equivalent" to a device on the market prior to May 28, 1976 (a "predicate device"). If a device being submitted is significantly different, relative to a pre-1976 device, in terms of design, material, chemical composition, energy source, manufacturing process, or intended use, the device nominally must go through a premarket approval, or PMA. A device that reaches market via the 510(k) process is not considered to be "approved" by the FDA. Nevertheless, it can be marketed and sold in the United States. They are generally referred to as "cleared" or "510(k) cleared" devices. A 2011 study by Dr. Diana Zuckerman and Paul Brown of the National Research Center for Women and Families, and Dr. Steven Nissen of the Cleveland Clinic, published in the Archives of Internal Medicine, showed that most medical devices recalled in the last five years for "serious health problems or death" had been previously cleared by the FDA using the less stringent, and cheaper, 510(k) process. In a few cases the devices had been deemed so low-risk that they did not need FDA regulation. Of the 113 devices recalled, 35 were for cardiovascular issues. This may lead to a reevaluation of FDA procedures and better oversight. Premarket approval (PMA) Premarket approval (PMA) is the most stringent type of device marketing application required by FDA. Unlike the 510(k) pathway, the maker of the medical device must submit an application to the FDA and must receive approval prior to marketing the device. The PMA application contains information about how the medical device was designed and how it is manufactured, as well as preclinical and clinical studies of the device, demonstrating that it is safe and effective for its intended use. Because the PMA requires a clinical trial it is significantly more expensive than a