SE Determination vs NSE Decision
Substantially Equivalent (SE) — cleared
When FDA issues an SE determination, the device is cleared and may be marketed in the United States. The decision letter:
- Identifies the device by K-number and device description
- States the intended use for which the device is cleared
- Identifies the predicate(s) relied upon
- Lists any special controls or conditions of clearance
The 510(k) summary is published in the FDA 510(k) database and is publicly searchable.
Post-clearance obligations:
- Register the establishment and list the device (if not already done)
- Comply with UDI labelling and GUDID submission requirements
- Implement QMS controls under QMSR
- Monitor for adverse events and MDR reporting obligations
- Evaluate future design or labelling changes against the 510(k) change threshold
Not Substantially Equivalent (NSE) — not cleared
An NSE determination means the device is not cleared and may not be marketed under this 510(k). An NSE is issued when:
- The device has a different intended use from the predicate
- The device has different technological characteristics that raise new questions of safety/effectiveness
- The performance data submitted is insufficient to support SE
Options after NSE
| Option | Description |
|---|---|
| Submit a De Novo request | If the device is novel but low-to-moderate risk — De Novo can create a new classification |
| Resubmit a 510(k) | With a different predicate, additional data, or a modified device |
| Submit a PMA | If the device is Class III — requires valid scientific evidence |
| Appeal the NSE | Request supervisory review within 30 days of the NSE determination |
| Modify the device | Change the device to eliminate the differences that caused NSE |
Challenging an NSE — the appeals process
A manufacturer who disagrees with an NSE determination may:
- Request supervisory review — an informal review by the next level of management within 30 days
- Submit a Dispute Resolution request to the Office of Device Evaluation (ODE)
- Request a formal meeting with FDA to discuss the basis for NSE