The 983 area code is the newest overlay serving the Denver metropolitan area and Boulder. Introduced in 2023, it was layered directly on top of the established 303 and 720 codes to supply fresh phone numbers across Colorado’s fast-growing Front Range.
Quick Summary of the 983 Area Code
| Area Code | 983 |
| State | Colorado (CO) |
| Region | Denver Metropolitan Area & Boulder |
| Major Cities | Denver, Aurora, Lakewood, Boulder, Arvada, Westminster, Thornton, Centennial |
| Time Zone | Mountain Time (MT) – MST / MDT |
| Dialing Format | 10-digit dialing required |
Geographic Coverage
The 983 area code shares an identical footprint with 303 and 720, covering the city of Denver and its suburbs of Aurora, Centennial, Lakewood, Arvada, Westminster, and Thornton, along with Boulder. As the newest overlay, 983 numbers can share the same street, and even the same building, as 303 and 720 lines.
Time Zone
The 983 area code observes Mountain Time (MT). Clocks follow Mountain Standard Time (UTC−7) in winter and shift to Mountain Daylight Time (UTC−6) from mid-March through early November. All of Colorado is on Mountain Time. From the West Coast, this region is one hour ahead of Pacific Time, so a 9:00 AM call in California reaches a 983 number at 10:00 AM local time.
Tip: Business hours across the 983 region generally run 9:00 AM to 5:00 PM Mountain Time, Monday through Friday.
How to Dial a 983 Number
Because area code 983 operates as part of an overlay, 10-digit dialing is mandatory for every local and long-distance call. You must dial the full 10-digit number (983 + the seven-digit line number) even when calling a neighbor across the street. For international callers, dial your country’s exit code, then +1 (the North American country code), then 983, followed by the seven-digit local number.
Scam Alerts for the 983 Area Code
Like every U.S. area code, 983 has been used by scammers who spoof local numbers to appear trustworthy. Residents in Denver, Aurora, Lakewood, Boulder, Arvada, Westminster, Thornton, Centennial should stay alert to the following common tactics:
| Scam Type | What to Watch For |
|---|---|
| IRS / Tax Scams | Callers impersonating the IRS and threatening arrest over supposed unpaid taxes. |
| Utility Shut-off | Fake Xcel Energy callers demanding instant payment to keep your power on. |
| Tech Support Fraud | Pop-ups or calls claiming your computer is infected and asking for remote access. |
| Bank Fraud Alerts | Robocalls impersonating your bank about “suspicious activity” to phish account details. |
If you receive a suspicious call from a 983 number, take these steps to protect yourself:
- Do not share personal information such as Social Security numbers, bank details, or passwords over the phone.
- Hang up and verify by calling the organization back using an official number from its website.
- Report the call to the FTC at reportfraud.ftc.gov and to the Colorado Attorney General’s Office.
- Block the number and consider registering with the National Do Not Call Registry.
Red Flag: Legitimate agencies such as the IRS, Social Security Administration, or your local utility company (Xcel Energy or Colorado Springs Utilities) will never demand immediate payment by gift card, wire transfer, or cryptocurrency. Any 983 caller making such a demand is a scammer.
History and Economy of the 983 Region
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The 983 area code entered service in 2023 as the third code – and second overlay – for the Denver metro, joining the original 303 (1947) and the 720 overlay (1998). By the early 2020s, the combination of the region’s rapid population growth, the spread of mobile phones, and demand for new business lines had exhausted the supply from the two earlier codes, so regulators added 983 across the same territory. The regional economy remains anchored by aerospace, technology, energy, telecommunications, and finance in Denver, along with the research labs, university, and startups of Boulder. Because 983 is the newest code in the region, it appears most often on recently activated mobile numbers and newly established business lines.
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Looking Up a 983 Number
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To identify a 983 caller, use a reverse phone lookup or search the full 10-digit number online. As the newest area code in the Denver metro, 983 numbers often have a limited public footprint, so treat unexpected 983 calls with extra caution and never share sensitive information with an unverified caller.
Nearby & Related Area Codes
Colorado is served by several area codes. If you are researching 983, these neighboring and overlay codes are worth knowing:
- 303 – Denver metro (overlay partner)
- 720 – Denver metro (overlay partner)
- 719 – Southern CO / Colorado Springs
- 970 – Northern & Western CO / Fort Collins
You can also browse our full directory of Colorado area codes for more regional guides.
↑ See the complete list of All US Area Codes by State – every area code across all 50 states in one directory.
Explore Neighboring States
Researching area codes just across the state line? Start with these codes in the states that border Colorado:
- Wyoming – area code 307
- Nebraska – area code 402
- Kansas – area code 316
- Oklahoma – area code 405
- New Mexico – area code 505
- Utah – area code 801
- Arizona – area code 602
Frequently Asked Questions
Where is the 983 area code located?
The 983 area code serves the Denver metropolitan area and Boulder as the newest overlay of 303 and 720, covering Aurora, Lakewood, Arvada, Westminster, Thornton, and Centennial.
Why does 983 cover the same area as 303 and 720?
983 is an overlay added in 2023 because the earlier 303 and 720 codes ran short of numbers. All three serve the exact same Denver-area region.
Do I have to dial 10 digits for 983?
Yes. Overlay area codes like 983 always require 10-digit dialing for local calls.
Is 983 a new area code?
Yes. Introduced in 2023, 983 is the newest area code in the Denver metro and observes Mountain Time (MST/MDT).
Related 983 Guides
- Worried about spam or robocalls? Browse our Scam Alerts directory.