Hello @Danielle B.
I have included a link that gives you a list of all the modems that are compatible with our service. It has a link inside of the article that will tell you which modem is best for you. I hope this helps. Once you get your new modem, you can either call in to speak with an agent or reach out to us with the make, model, serial number, and MAC address. This way the new modem can be added to the account and activated. This can be done at Cox.com as well. Please make sure that you return the rental modem to the nearest Cox Solution Retail store so that you are not charged for that equipment. You can reach us on Twitter at @CoxHelp, visit us on Facebook, or email us at cox.help@cox.com.
www.cox.com/.../cox-certified-cable-modems.html
Crystal S.
Cox Support Forum Moderator