Modem Compatability

Does anyone know if you can use an Apple modem with Xfinity Comcast?

Apple does not, and has not offered a modem. Apple did offer a line of 3 AirPort WiFi routers......(which did not have built in modems).......but these models have all been discontinued as of April 2018.

Perhaps you have one of the Apple AirPort routers? If yes, can you provide the model number of the Apple device?

It would also really help us if you could provide the model number of the Xfinity device that you have.

Please provide more details on what you are calling an "Apple modem".

Model and part number would really help.