A Class III medical device is one FDA considers the highest risk category (typically life-supporting, life-sustaining, or implanted), or one where neither general nor special controls provide sufficient assurance of safety and effectiveness under 21 CFR 860.3. Class III devices generally require Premarket Approval (PMA), FDA's most rigorous device review pathway.
The Legal Standard
Under 21 CFR 860.3, a device is Class III when there is insufficient information to determine that general controls, or general controls together with special controls, provide reasonable assurance of safety and effectiveness, and the device is purported to be life-supporting or life-sustaining, is for a use of substantial importance in preventing impairment of human health, or presents a potential unreasonable risk of illness or injury.
What Premarket Approval Involves
PMA is FDA's most extensive premarket review pathway. Rather than the substantial-equivalence comparison used in a 510(k), a PMA requires valid scientific evidence that the device is safe and effective for its intended use. For most Class III devices, this includes clinical data, alongside nonclinical data, complete manufacturing information, and labeling.
Exceptions to the PMA Requirement
Not every Class III device type is currently required to go through PMA. A small number of preamendments Class III device types (those on the market before the Medical Device Amendments of 1976, and devices substantially equivalent to them) can still reach the market through 510(k) until FDA issues a final order under section 515(b) of the FD&C Act requiring PMA for that type. New device types determined to be Class III generally require PMA from the outset. A device with no valid predicate that could otherwise be regulated through general or special controls may instead be eligible for the De Novo pathway rather than automatic Class III designation.
How This Differs From Class I and II
Class I relies on general controls alone; Class II adds special controls and typically a 510(k). Class III is reserved for devices where neither is judged sufficient, given the device's role in supporting or sustaining life or the level of risk it presents. See the full comparison of Class I, II and III.
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See 513(g) & Classification Book a Free ConsultFrequently Asked Questions
Do all Class III devices require PMA?
Most do, but a small number of preamendments Class III device types can still use 510(k) until FDA issues an order requiring PMA for that type. New Class III device types generally require PMA from the start.
Can a Class III device ever use the 510(k) pathway?
A novel device with no predicate is Class III by default. It may be eligible for the De Novo pathway if general controls, or general and special controls, can provide reasonable assurance of safety and effectiveness; otherwise it remains Class III and PMA applies.
What does FDA review in a PMA?
FDA reviews valid scientific evidence of safety and effectiveness, which for most Class III devices includes clinical data, along with manufacturing information, nonclinical data, and labeling: a substantially more extensive review than a 510(k) substantial equivalence comparison.