Cell phone provider promotions change a lot these days, and most companies now offer monthly contracts. Call around and switch as often as you wish to keep your cell phone bill low and service high!
Bottom line is all providers are one of 4 carriers: Verizon, ATT, T-mobile, or Sprint. The big carriers often roam customers to each other as they travel. However, if you go with a reseller, you won’t switch networks as you roam around, so look at coverage maps for each of the underlying providers and decide which you want for where you go. If two resellers are for the same underlying provider, the coverage will be the same between the resellers.
The big coverage differences are in the expansive land areas out west. Sprint seems to favor big interstates. T-mobile coverage sprinkles over an area and Sprints’ is more in blobs. AT&T and Verizon are very similar in that they seem to ooze out of larger metropolitan areas, with Verizon just a little bit better, but the difference was irrelevant for me.
The coverage link below says Sprint, but click into the map and you can choose other carriers. To know for sure, you should probably just sign up for a month ($20 and up) and test each carrier you’re considering. If you have experience different than the maps show, it could be a very local shielding problem. You may benefit from shifting to other frequencies (ATT v. Verizon, or 5G) that bounce around, absorb, and propagate differently. Coverage maps for 3G or 4G or 5G are different for this reason.
https://www.whistleout.com/CellPhones/Guides/sprint-coverage-map
Check the list of resellers every month or so and switch to whoever has the best deal. Most are now no-contract monthly subscriptions.
https://bestmvno.com/mvnos/
Sorting the MVNOs by underlying carrier:
https://bestmvno.com/compare/t-mobile-mvnos/
https://bestmvno.com/compare/sprint-mvnos/
https://bestmvno.com/compare/att-mvnos/
https://bestmvno.com/compare/verizon-mvnos/