Area codes in Johnson City, Tennessee
Johnson City, Tennessee uses 2 area codes — 423 and 729. The main Johnson City area code is 423.
Area codes serving Johnson City
Phone numbers in Johnson City are written as ten digits — for example (423) 555-0190 — and fall in the Eastern Time zone.
How Johnson City came to have 2 area codes
The original Johnson City area code is 423, in service since 1995. As the area ran low on available numbers, an overlay code was added over the same region for new phone lines: 729 (2025). Existing numbers kept their original code — an overlay never forces anyone to change their number — which is why Johnson City now uses all 2 codes and every local call is dialed with ten digits.
All Tennessee area codes · Is a Johnson City call a scam?
Nearby cities
- Kingsport area codes
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- Morristown area codes
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More cities in Tennessee
- Nashville area codes
- Memphis area codes
- Chattanooga area codes
- Clarksville area codes
- Murfreesboro area codes
- Cookeville area codes
- Hendersonville area codes
Frequently asked questions
What is the area code for Johnson City?
The main area code for Johnson City, Tennessee is 423. Johnson City is now served by 2 area codes in total: 423, 729.
How many area codes does Johnson City have?
Johnson City has 2 area codes: 423, 729.
Why does Johnson City have more than one area code?
As Johnson City used up the numbers available in its original area code (423, in service since 1995), additional "overlay" codes were added over the same area so new phone numbers could keep being assigned.
How do you dial a Johnson City number?
Dial all 10 digits — the area code (423 or 729) followed by the 7-digit local number. From abroad, dial +1, then the area code and number.
Sourced from the official NANPA (North American Numbering Plan Administrator) numbering database, current as of August 2, 2026. Refreshed monthly.