I had to switch to Comcast/Xfinity and it took me a month to track down a cablecard to get my Tivo working again. Comcast is no longer mailing out their Cablecard starter kits they way they used to. I talked to quite a few Comcast ambassadors, Tivo and Cablecard specialists in this process and discovered that their computer system no longer has even a code to get one to you in the mail. The first CSR said they don't support Cablecard anymore. But trying over and over I randomly was connected to a CSR in Seattle and another in Everett WA who gave me ideas to somehow get a Cablecard. They said I could not activate a second hand card bought on EBay.
The first suggestion was to set up an appointment for a technician to bring a cablecard to my address. That didn't work. No technician in my area even had a card to bring out. The next suggestion was to visit different Xfinity locations to see if they had one in inventory. Cablecard inventories are not even listed on the CSR's computer system -- but, maybe an office somewhere has one.
Everywhere I went I was told to just move on to something new and Tivo is over and obsolete and the cloud DVR is better anyway. They are probably right. The AppleTV app, "Xfinity Stream" can do it all and do it very well. The Xfinity DVR boxes likewise have become very nice and easy to use.
However, I did find an office that had a cablecard someone had returned. They would not issue it to me. I persisted and found a manager that persuaded that office to issue me the old card anyway and put it in the system and add it to my account to try with no guarantees.
Getting it paired was another matter. Took lots of time and many calls but one CSR finally helped me and didn't give up as all the others did and paired and activated it. At first, just the basic channels local channels were decoded, but none of the others. Took about a half hour before multiple re-hits authorized all the channels. But, It's all working perfectly now. Tivo is still alive. A small miracle in my mind.