West region · Mountain Time
Montana Area Codes
All 1 area code serving Montana, the cities each one covers, and which are overlays. Montana is served by 1 area code in the Mountain Time zone.
Last updated June 5, 2026
Full list
Every Montana area code
Montana is served by 1 area code in the Mountain Time zone. It is a single-code state, so seven-digit local dialing may still work in many places.
| Code | Main city | Type | Status |
|---|---|---|---|
| 406 | Billings | Geographic | In service |
Area codes and dialing in Montana
Montana is one of the few US states still covered by a single area code, 406. Because there's no overlap, many local calls can still be completed with seven digits, although dialing the full 10-digit number always works and is the safer habit. 406 serves Billings and the rest of the state, all in the Mountain Time zone.
If Montana ever exhausts its supply of numbers, regulators would almost certainly add an overlay rather than split the state — the modern approach that lets everyone keep their existing number. For now, every Montana number shares the 406 code. Learn the background in how area codes work.
Browse Montana another way
Explore by West region, by time zone, or jump to the city index. You can also see the complete numeric list of every US area code.
Quick answers
Montana area code FAQ
How many area codes does Montana have?
Montana currently has 1 area code: 406.
What is the main area code for Montana?
The busiest metro in Montana is served by the 406 code. Major cities include Billings.
Does Montana require 10-digit dialing?
Much of the state still permits 7-digit local calls, though 10-digit dialing always works. Ten-digit dialing is the national standard.