| Categories | Description |
|---|---|
| Pre-amendment | devices that were marketed prior to May 28, 1976 (the date the MDA was signed into law) |
| Post-amendment | devices that were approved by the FDA after the MDA was enacted |
| Substantially Equivalent | devices that are substantially equivalent to pre-amendment devices based on their design, materials, and intended use |
| Implant | devices that are inserted into a surgically formed or natural body cavity and intended to stay for at least 30 days. |
| Custom | devices generally not available to other licensed practitioners and not available in finished form |
| Investigational | devices undergoing clinical investigation under the authority of an Investigational Device Exemption from the FDA |
| Transitional | devices which were regulated as drugs prior to the Medical Device Amendments but are since regulated as devices |