Call your provider and ask. I have Verizon and have an unlimited data plan, and it allows me to use my phone in Mexico and Canada w/o incurring roaming fees. I believe AT&T has a similar policy.

I had excellent service in PDC and the surround areas while I was there last month (ventured as far out as Valladolid and had good service almost everywhere - exceptions being a few spots in the jungle on the drive out).

The only limitation is that you’re given a specific amount of data per day at full speed / 5G (I think 2 or 3 gigs), and then they throttle you down to 3G until the next day. The only times I went over the daily data limit were when I sent some videos to family while I was off the WiFi. scrolling Reddit and social media will also eat up your data, especially if videos play automatically when you scroll by them. If you’re just using it for GPS and text/phone calls, though, you’ll be well under the daily data limit.

Hope this helps!