406 Area Code — Montana

406 is a North American Numbering Plan area code for Montana, the United States. It covers about 1,116,057 people in 342 towns and 386 ZIP codes, including Billings, Missoula and Bozeman.

Where area code 406 is used

Area code 406 is assigned to Montana, the United States, inside the North American Numbering Plan. Numbers in the code are written (406) NXX-XXXX at home and +1 406 NXX-XXXX when dialled from outside Canada and the United States. Since the NANP moved to 10-digit dialling you must always include the area code, even for a local call.

Towns and cities in area code 406

The 342 towns below are the largest in the 406 footprint, ranked by population. Every one of them links to its own page with the full list of area codes and ZIP codes for that town.

Counties covered

Nearby area codes

How to dial area code 406

• Within North America: 406 + 7-digit number (406-NXX-XXXX). The leading 1 is optional on a mobile phone and required on most landlines for long-distance.
• From abroad: your country's international prefix, then 1, then 406, then the 7-digit number — for example 00 1 406 NXX-XXXX from most of Europe.