Premarket approval (PMA) is the method by which the Food and Drug Administration reviews new medical devices and medications. A PMA is granted only when the manufacturer is able to demonstrate safety and efficacy by means of “adequate and well-controlled” studies, conducted under strict clinical conditions. Only then may the manufacturer begin selling the product.

A PMA is required for any medical device that is categorized as Class III, which is intended to keep a patient alive or prevent an adverse event, is surgically implanted in the patient's body, and may pose a certain amount of risk to the patient's health and well-being. Pacemakers are the most well-known and commonly used Class III devices; other examples include artificial joints, meshes used to repair internal injuries, and blood filters inserted into an artery (intended to prevent embolism and reduce the risk of stroke). Approximately 10% of all medical devices and products fall under the Class III category.

Unlike the 510(k) process, PMA is very stringent, expensive, and time-consuming for the manufacturer. Some devices are exempted from PMA if they have a proven track record of safety and efficacy and were on the market prior to 1976. Otherwise, the device in question must undergo careful study under laboratory conditions.

Ideally, this is a meticulous, step-by-step process that begins with computer and machine simulations and bench tests or, in the case of new drugs, test tubes and petri dishes. If these preliminary tests produce the hoped-for results, the next step is animal testing. This helps to determine how the new drug or device responds under biological conditions.

Human trials are the final step. However, before these are legally allowed to take place, the company must file a special application with the FDA (in the case of experimental medications, this is known as an IND, or “investigational new drug” application). This application undergoes FDA review before human testing begins – and the agency can put a stop to that testing at any time.

The PMA process is also costly, particularly in the case of medical devices. It can cost $94 million on the average before a medical device can be put on the market, and can take a year or more. In contrast, going through the 510(k) route costs less than a third of that amount and takes half as long – which is why most manufactures prefer to use that process whenever possible.

There is a distinct advantage to completing the PMA process, however. If a device has been subject to premarket approval by the FDA, it makes it much more difficult for injured parties to bring lawsuits because of the legal doctrine of preemption, found in Article VI, Section 2 of the Constitution. This essentially means that federal laws and regulations (in this case, formal FDA approval) takes precedence over state and local law. On the other hand, the courts have ruled that such preemption is inapplicable to devices that have been cleared under Section 510(k). This means that if a 510(k) device proves to be injurious, parties who have been affected have a much stronger case should they decide to pursue legal remedies.