Getting a CableCARD is getting harder and harder as cable providers aren't legally required to give them out anymore, but some still give out CableCARDs.
AT&T/DIRECTV:
Difficulty: Impossible
As far as I know, AT&T/DIRECTV doesn't give out CableCARDs. They used to make TiVos that only worked with DIRECTV, but not anymore. Maybe the TiVo THR22 can still be used?
Comcast/Xfinity:
Difficulty: Easy
2 friends of mine were able to call and ask for a CableCARD really easily and be able to pick it up in their local Xfinity store. 1 of them had to go back and ask again for them to ship one out because they didn't.
Frontier:
Difficulty: Medium
I was able to get a CableCARD with Frontier in summer 2021. I first talked to a live chat agent who adjusted my billing to fit a CableCARD in, and they said they would ship it. It wasn't shipped until I called a week or so after, and then they were able to ship it and give a UPS tracking number. The next day, I received an Arris CableCARD, and was able to successfully pair it with the TiVo after some hiccups. They've said they want to phase out CableCARDs though.
Spectrum:
Difficulty: Hard
It's hard to get a CableCARD with Spectrum. A few months ago, someone had to speak with 15 different representatives on Spectrum's customer support line until 1 was able to send someone to install a CableCARD. 10 agents said that they couldn't send one out because their supervisor said they can't, and 4 said they would send one out but weren't able to. After there was an agent who could get them one, an appointment was scheduled and 3 guys came over to their house just to insert it and pair it.
Suddenlink:
Difficulty: Very Hard
In 2021, someone on TiVoCommunity was trying to get a CableCARD, and it took a complaint to the FCC to send one and several hours on the phone. See kpascuch's post here: Warning for Suddenlink customer considering...
Verizon:
Difficulty: Very Easy
Verizon has everything set up to let you get a CableCARD. See CableCARDS
AT&T/DIRECTV:
Difficulty: Impossible
As far as I know, AT&T/DIRECTV doesn't give out CableCARDs. They used to make TiVos that only worked with DIRECTV, but not anymore. Maybe the TiVo THR22 can still be used?
Comcast/Xfinity:
Difficulty: Easy
2 friends of mine were able to call and ask for a CableCARD really easily and be able to pick it up in their local Xfinity store. 1 of them had to go back and ask again for them to ship one out because they didn't.
Frontier:
Difficulty: Medium
I was able to get a CableCARD with Frontier in summer 2021. I first talked to a live chat agent who adjusted my billing to fit a CableCARD in, and they said they would ship it. It wasn't shipped until I called a week or so after, and then they were able to ship it and give a UPS tracking number. The next day, I received an Arris CableCARD, and was able to successfully pair it with the TiVo after some hiccups. They've said they want to phase out CableCARDs though.
Spectrum:
Difficulty: Hard
It's hard to get a CableCARD with Spectrum. A few months ago, someone had to speak with 15 different representatives on Spectrum's customer support line until 1 was able to send someone to install a CableCARD. 10 agents said that they couldn't send one out because their supervisor said they can't, and 4 said they would send one out but weren't able to. After there was an agent who could get them one, an appointment was scheduled and 3 guys came over to their house just to insert it and pair it.
Suddenlink:
Difficulty: Very Hard
In 2021, someone on TiVoCommunity was trying to get a CableCARD, and it took a complaint to the FCC to send one and several hours on the phone. See kpascuch's post here: Warning for Suddenlink customer considering...
Verizon:
Difficulty: Very Easy
Verizon has everything set up to let you get a CableCARD. See CableCARDS