Premarket approval is the U.S. Food and Drug Administration (FDA) process of scientific and regulatory review to evaluate the safety and effectiveness of Class III medical devices and is significantly different from the Premarket Notification process known as 510(k). Class III devices are those that support or sustain human life, are of substantial importance in preventing impairment of human health, or which present a potential, unreasonable risk of illness or injury. Due to the level of risk associated with Class III devices, FDA has determined that general and special controls alone are insufficient to assure the safety and effectiveness of class III devices. Therefore, these devices require a PMA) application under section 515 of the FD&C Act in order to obtain marketing clearance. Note that some Class III preamendment devices may require a Class III 510(k).

Device classes

• Class I: Must only follow FDA general controls, no 510(k) or PMA needed.
• Class II: Use the 510(k) process which uses a pre-existing similar device in the market called a "predicate device" for comparison.
• Class III: Use the PMA process whereby no "predicate device" exist, such as in a New Drug Application
  New drug application
  The New Drug Application is the vehicle in the United States through which drug sponsors formally propose that the Food and Drug Administration approve a new pharmaceutical for sale and marketing...
  
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