Do I need FCC certification to sell if my device uses ISM bands?
All intentional radiators must be certified to the FCC regulations.  Since you said "transceiver", it implies this device is in part a transmitter.  Selling a intentional radiator, such as your device, without FCC certification in the United States is a federal offense.  All your units can be confiscated, you can be fined, and in some cases worse punishments may be imposed.

Frankly, if you are asking such a basic question, you don't belong in this position.  Get someone who knows what they are doing to help you thru the process.  Then maybe next time you can be the expert.  This really not a place newbies belong without the guidance of someone that does know what they are doing.