During acceptance review, the FDA assesses the completeness of the application and whether it meets the threshold of acceptability. In 15 days, the FDA will notify the submitter about whether the application has been accepted for substantive review, not accepted (RTA) and the requester has 180 days to address the RTA, or if the application is under substantive review and FDA didn’t complete acceptance review within 15 days.

During substantive review, the FDA first conducts a classification review to see if an existing legally marketed device of the same type exists. They may identify deficiencies to resolve, in which the requester has 180 days to submit additional information. The De Novo request decision will be given in 150 review days. In detail, there are four actions the FDA can take during the substantive review process:

• Granting the Request: The device meets the criteria for either Class I or II. This authorizes marketing of the device and marks the end of the review clock.
• Declining the Request: The device either is not eligible for De Novo classification, the requester has not adequately demonstrated that it is eligible, or that general/special controls are sufficient to mitigate potential risks. This is a final action.
• Request for Additional Information: When a De Novo request lacks information necessary to complete substantive review. This is issued with an attachment identifying deficiencies and places the request on hold until a response is received.
• Notice of Withdrawal: This informs the FDA that the request has been withdrawn and represents the decision to discontinue review. FDA considers a request withdrawn if it does not receive a response to additional info within 180 days or the request.

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