De novo classification (513(f)(2) of the Federal Food, Drug, and cosmetic act) provides a pathway to Class I or Class II classification for medical devices for which general controls or general and special controls provide a reasonable assurance of safety and effectiveness, bur for which there is no legally marketed predicate device.
https://www.fda.gov/downloads/medicaldevices/deviceregulationandguidance/guidancedocuments/ucm273903.pdf
When a completely new device is introduced to the market it is automatically classified as a Class III in the US. If the device is not considered a high risk you may use the FDA process known as “de Novo”. The “de novo” submission will have the FDA review your submission through means of 5139(g) or Pre-submission. It the FDA determines that your device is a “novel” with no existing classification or predicate device the FDA may classify your device as a Class I or Class II and may issue an entirely new product code and regulation number. Just keep in mind you cannot submit a de Novo and a 510(k) at the same time. The FDA searches its database upon receipt of a de novo submission. If the FDA determines that you have submitted your device for review under a 510(k) for the same intended use, your de novo submission will be rejected
https://www.emergogroup.com/services/united-states/fda-device-classification
The new ruling is actually a game changer compared to the old process. It seems the old process used to force you to take a certain path even if your device was not a high risk one. The de novo process will enable companies bring more innovative low risk products to market and can establish limited barriers to entry for competitors
https://www.morganlewis.com/-/media/files/publication/presentation/webinar/2017/fda_de-novo-pathway_9march17.ashx