US eSIM guide: networks, coverage and setup
The US has three national networks with 5G in most populated areas, but large rural and national-park areas have little or no signal.
Get an eSIM
Local networks
- VerizonLarge nationwide network, known for broad rural coverage.
- AT&TLarge nationwide network with broad coverage.
- T-MobileLargest mid-band 5G footprint; strong in cities.
5G5G is widespread in cities and suburbs on all three networks. 3G has been fully switched off (2022-2024), so the phone must support 4G/VoLTE.
Must-knows
- Download offline Google Maps for national parks and long drives; many parks have no signal.
- Uber and Lyft accept foreign numbers, but SMS verification needs your Korean line to be on.
Buying a local SIM
Prepaid SIMs are sold at carrier stores, big retailers and some airports. The US does not require prepaid SIM registration.
Weak-signal areas
Good in cities and along interstates. Coverage gaps are common in national parks (Yellowstone, Grand Canyon backcountry, Death Valley), deserts and mountains in the West.
How much data do you need?
Pick a plan of about 3.6 GB