What is 406 Area Code?

The 406 area code is the original and only area code for the state of Montana. Unlike most states that have added multiple area codes due to population growth, Montana continues to operate with just one. Having a 406 number can help your business appear local, connect with customers more effectively, and build stronger relationships in the Montana market.

  • State: Montana
  • Major Cities: Billings, Missoula, Great Falls, Bozeman, Helena
  • Time Zone: Mountain Standard Time (MST) / Mountain Daylight Time (MDT)
  • Established: 1947 (one of the original area codes under the North American Numbering Plan)
  • Overlay Area Code: None (406 covers the entire state)
  • Region Population: Approx. 1.1 million
  • Primary Uses: Statewide coverage for landlines, mobile phones, VoIP, and business numbers

Regions Covered by 406 Area Code

The 406 area code covers all Montana cities, from large urban centers to small rural communities. Here’s a list of cities under the 406 area code:

Yellowstone County
  • Billings
  • Laurel
  • Huntley
  • Worden
  • Shepherd
Missoula County
  • Missoula
  • Bonner
  • Frenchtown
  • Seeley Lake
  • Olney
Flathead County
  • Kalispell
  • Columbia Falls
  • Bigfork
  • Lakeside
  • Somers
  • Whitefish
Silver Bow County
  • Butte
  • Walkerville
  • Centerville
  • Meaderville
  • Dublin Gulch
Cascade County
  • Great Falls
  • Black Eagle
  • Fort Shaw
  • Stockett
  • Ulm
Hill County, Montana
  • Havre
  • Hingham
  • Inverness
  • Gildford
  • Kremlin
  • Box Elder
  • Rudyard
Gallatin County
  • Bozeman
  • Belgrade
  • Big Sky
  • Manhattan
  • Three Forks
Lewis and Clark County
  • Helena
  • Augusta
  • East Helena
  • Wolf Creek
Fergus County
  • Lewistown
  • Denton
  • Moore
  • Roy
  • Grass Range
Custer County, Montana
  • Miles City
  • Ismay
  • Volborg
  • Kinsey
  • Hathaway

Population & Demographics of 406 Area Code

The 406 area code region serves Montana’s population of roughly 1.1 million people spread across a large geographic area. The state is known for its mix of urban centers, agricultural communities, and Native American reservations.

The population density is one of the lowest in the country, which explains why a single area code continues to serve the entire state. Businesses that use a 406 area code number can connect with a wide range of customers across both rural and metropolitan areas.

406 Area Code Time Zone

The 406 time zone is the Mountain Time Zone (MT). This means that all calls and business operations in the region follow Mountain Standard Time (MST) or Mountain Daylight Time (MDT), depending on the season. Businesses operating with a 406 area code should keep this in mind when coordinating with partners or clients in other time zones.