Types of FDA clearance for Medical Devices (and their differences).

March 2025 , Sam Moreland

This is a quick blog post outlining the different types of FDA clearance and their effects on time to market. Note that the time to clearance/approval are the realistic timescales. The FDA have a requirement to address submissions within certain time periods, this does not mean you will get cleared/approved in that time. Usually there is some pushback or something you get wrong and this is especially true for new companies.

There are 4 main methods of regulatory approval (excluding HDE):

Class I Devices, Exempt from Premarket Notification 510(k) (Low Risk): Most Class I devices do not require FDA review before being marketed but must comply with general controls (e.g., labelling, manufacturing standards). Note you still need to have a QMS in place, you are not absolved from this.
Examples: Bandages, adhesive tape.

Class II Devices, 510(k) Premarket Notification (Moderate Risk): Required for most Class II devices where the manufacturer must demonstrate that the device is substantially equivalent to a legally marketed device (predicate device). Clearance does not require clinical trials unless human data is necessary to show equivalence. Note that even though there is a historical route to market including validation, the FDA can change their requirements for the process (usually increasing validation requirements) as they learn more about the real world outcomes of the device.
Examples: Heart rate algorithms, diagnostic imaging tools.
Time to clearance: 6-12 Months

Class II Devices, De Novo Pathway (Moderate Risk, No Predicate): For novel devices with no predicate device but deemed low-to-moderate risk.The device must meet special controls and general safety requirements. Used when a device is not eligible for 510(k) but doesn't require a PMA.
Time to approval: 1-3 Years

Class III Devices, Premarket Approval (PMA) (High Risk): High risk means life-supporting or life-sustaining devices. Involves comprehensive clinical trials to demonstrate safety and efficacy.
Examples: Pacemakers, artificial hearts and likely AI directed treatment.
Time to approval: 1-3+ years.