PureTalk uses AT&T. It has national coverage and 5G data coverage. The plans start at $20 monthly. All plans include unlimited talk and text, and there are no contracts or data overage charges. A benefit of PureTalk is that you can use your phone and keep your existing number if you want to.
If you need a new phone, you can choose from hundreds of Samsung, Apple, Nokia, and ZTE models and get a discount when you sign up for a plan. There are no fees for activation and no hidden charges.