US area code map
This page is a text explanation of how area codes are distributed across the United States, grouped by time zone. It is not a geographic map image, and it does not claim to show boundaries on a map. Boundaries for area codes follow telephone numbering areas, not state lines alone, and a single state can contain several area codes in different regions. The examples below are Batch 1 codes only, grouped by the time zone of each code’s region.
Eastern Time
The Eastern Time examples in the first set are concentrated in the east and south-east. 201 covers northeastern New Jersey, 212 covers Manhattan in New York City, and 347 covers the outer boroughs of New York City. 305 covers Miami-Dade and the Keys in Florida, 404 covers inner Atlanta in Georgia, 412 covers the Pittsburgh area in Pennsylvania, 513 covers the Cincinnati area in Ohio, 616 covers the Grand Rapids area in Michigan, 617 covers the Boston area in Massachusetts, 703 covers Northern Virginia, and 704 covers the Charlotte area in North Carolina. A code in this group does not cover its whole state; each code page gives the region that code actually serves.
Central Time
The Central Time examples in the first set are 214, covering the Dallas area in Texas, 312, covering downtown Chicago in Illinois, and 615, covering Nashville and Middle Tennessee. Texas and Tennessee are both split between time zones, so the Central Time label here applies to each code’s own region, not to the whole state. The Dallas, Chicago, and Nashville regions are separate numbering areas, and their codes do not overlap.
Mountain Time
The Mountain Time examples in the first set show the one clear exception in this group. 720 covers the Denver-Boulder area in Colorado and follows Mountain Time, which moves between Mountain Standard Time in winter and Mountain Daylight Time in summer. 602 covers the Phoenix area in Arizona and stays on Mountain Standard Time all year, because Arizona does not observe daylight saving time. The two codes are therefore both described as Mountain codes, but a call time that is correct for Denver in summer will not be the same clock time in Phoenix.
Pacific Time
The Pacific Time examples in the first set are on the west coast. 206 covers the Seattle area in Washington, 213 covers central Los Angeles in California, 310 covers the Westside and South Bay in California, and 702 covers Clark County and Las Vegas in Nevada. California has two codes in this first set, but they cover different parts of Los Angeles County, so a Los Angeles number’s code still matters: 213 and 310 are not interchangeable, and each code page gives its own region and overlay group.
How to read this distribution
First, find the code, not just the state. Second, check the code page for its region, because neighbouring codes in the same state can cover different cities. Third, check the time zone on the code page before calling across zones, and remember the Arizona exception: a Mountain Time code in Arizona does not shift with daylight saving time in the way a Mountain Time code in Colorado does. As more verified codes are added, each time-zone group on this page will grow, but no code will be added to a group until its region and time zone have been checked.
Frequently asked questions
Is there a map image on this page?
No. This page explains the distribution in text, grouped by time zone, with links to code pages. It does not present a geographic map or claim to show exact boundaries.
Why are codes grouped by time zone here?
Because the most common practical question after ‘where is this code’ is ‘what time is it there’. Grouping by the code’s own time zone answers that question directly, without implying that a whole state shares one zone.
Will this page change as more codes are added?
Yes. Each time-zone group will add codes only when those codes have been checked. The page will not list a code as an example before its facts are verified.
Sources: NANPA Area Code Search tool; NANPA planning letters cited on the Batch 1 code pages.
Based on a recent search of NANPA and official sources.
This website provides general information about North American area codes, compiled from public sources including NANPA. It is not affiliated with or endorsed by the FCC, NANPA or any telephone carrier. Area code details can change; confirm with your carrier or the official NANPA website. This site does not identify callers or phone owners.