Starting October 18th, 2021 T-Mobile, and Metro (by T-Mobile) will be available in roughly half of all Walmart locations in the United States.
The “over 2300,” Walmart locations T-Mobile lists in their press release adds on to 20,100 other locations (2,200 direct owned, 13,300 exclusive 3rd party, 4,600 non-exclusive 3rd party,) that you can conduct some forms of business with T-Mobile & Metro by T-Mobile at.
No word on if this is an exclusive relationship or if Walmart will attempt to woo other carriers. Also not listed is exactly what levels of service these are going to be. Simply selling plans, paying, dealing with issues, repairs, etc?