Visit the T-Mobile store in Rancho Cucamonga and discover America’s largest, fastest, and most reliable 5G network. Shop our best low-cost plans with no annual service contracts - plus our best smartphones, cell phones, tablets, internet devices, and latest promotions. If you’re interested in joining the Un-carrier, our staff at 6403 Haven Ave Suite 102 can assist you in the switching process. Masks are optional for fully vaccinated guests except where state or local ordinances require all guests wear a mask at all times.