Once a settlement is reached and a preliminary class certified, all class members should receive notice of the settlement and can fill out a form to submit a claim. Class settlements can be structured differently, but typically, the company pays the same settlement amount regardless of the number of claims submitted. Most of the time, the entire settlement amount is divvied out by the number of claimants. So whether you join or not makes no difference. If you don't join, generally the other claimants just receive more. Very rarely do left over funds revert back to the defendant.