Montana Area Codes
1 active area code · Billings · Population around 1,137,557
Montana has 1 active area code, serving cities like Billings, Missoula, and Great Falls. 406 has covered the whole of Montana since 1947. Each code below links to its cities, carriers, timezone, and coverage map.
Montana Area Code Map
What area codes does Montana have?
Every one of the 56 counties in Montana is covered by this code and no other.
How many phone prefixes does Montana use?
Montana's area code holds 741 assigned prefixes, listed under 60 distinct carrier names. A prefix is the three digits after the area code, and NANPA assigns each one to a single carrier.
Sources: City populations – U.S. Census Bureau PEP, Vintage 2024 (SUB-IP-EST2024-POP). State populations – the same program, Vintage 2025 (CO-EST2025-ALLDATA). Area-code footprint and county populations – 2020 Census Centers of Population, mapped against NANP area code boundaries. The share of each city inside a code is measured the same way, against Census place boundaries from the Census Bureau's TIGERweb service. Area code assignments – NANPA CO Code data. See our data methodology.
Frequently Asked Questions
How many area codes does Montana have?
Montana has 1 active area code: 406.
What is the main area code for Montana?
Montana has a single area code, 406, in service since 1947. It covers Billings, the largest city in Montana, and every county in Montana.
What are the largest cities in Montana?
The largest cities in Montana include Billings, Missoula, Great Falls, Bozeman, Helena.
What is the total population of Montana?
Montana has an estimated total population of 1,137,557 based on US Census PEP 2024 data.
What is the newest area code in Montana?
406, in service since 1947. It is the only area code in Montana.
Is my county covered by more than one area code in Montana?
No. All 56 counties in Montana are covered by 406, so no county here carries two.