US Area Code Statistics
Comprehensive data on the US telephone numbering system. From 77 area codes assigned in 1947 to today's 376 codes, explore how the system has evolved.
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US Area Codes by the Numbers
Active area codes = US + Puerto Rico (376 total in database, 376 in family tree). Other pages may show different counts: the Exhaustion Study includes Canadian and special-purpose codes (361), while the Income & Density Study covers only US codes with Census data (194).
Methodology note: The "Assigned in 1947" count (77) refers specifically to area codes whose in-service date falls within 1947 — the year the North American Numbering Plan was launched. The Family Trees page shows 100 "Root Codes" because it includes all codes with no parent (independent assignments after 1947), not just the original 1947 allocations. Population and density charts use only geographic and split codes (excluding overlays) to avoid counting the same region twice.
Data coverage: Demographic statistics (population, income, education, poverty) are available for 194 geographic and split area codes (out of 236 total). Population and density charts use these same codes: the scatter plot shows 194 data points, and the density-by-state map covers 194 codes — small differences due to Puerto Rico and data source variations. The remaining 182 codes lack Census ACS demographic data. See Sources for details.
Population note: Population figures are derived from county-level Census data mapped to area codes via geographic boundaries. These are approximate — the Census Bureau does not publish population data at the area code level. In overlapping metro areas, the same population may appear under multiple area codes. See Sources & Methodology for details.
The Evolution of US Area Codes
In 1947, AT&T and the Bell System introduced the North American Numbering Plan, assigning 77 original area codes assigned in 1947. Each NPA was assigned a 3-digit code using a formula that made the most populated cities easiest to dial on rotary phones.
The 1990s saw the most new area codes with 109 created, driven by mobile phone and fax demand. The 1990s alone produced 109 codes. Since 2000, overlays (138 total) have largely replaced splits (136 total), preserving existing numbers while adding capacity. Of the 374 area codes with activation dates, 100 were original geographic codes, 136 were created by splitting existing area codes, and 138 were created as geographic overlays. 2 additional codes are reserved but not yet in service (e.g., 565 GA, 761 KY).
Key Findings
- Our database covers 376 US area codes (374 in service), up from 77 area codes assigned in 1947.
- 136 codes were created by splits, while 140 were created as overlays.
- The average utilization across all area codes is 61.8%.
- 158 area codes are above 90% utilization, indicating they may need relief planning soon.
- Since 2000, most new area codes have been overlays rather than splits, preserving existing numbers while adding capacity.
Relief Planning Status
Area codes currently in or approaching exhaust status.
| Code | State | Relief Planning | Expected Exhaustion |
|---|---|---|---|
| 502 | KY | Yes | — |
| 565 | GA | Yes | — |
| 626 | CA | Yes | — |
| 657 | CA | Yes | — |
| 714 | CA | Yes | — |
| 761 | KY | Yes | — |
| 828 | NC | Yes | — |
| 912 | GA | Yes | — |
| 956 | TX | Yes | — |
9 area codes listed from NANPA Relief Planning Reports (9 US, 0 international). Of the US codes, some are reserved overlays not yet in service (e.g., 565 GA, 761 KY) and therefore do not appear in the Exhaustion Study's utilization rankings.
Reserved Area Codes
Area codes that have been assigned by NANPA but have 0% prefix utilization — they are reserved for future use and are not yet active. These codes do not appear in the Exhaustion Study's utilization rankings.
| Code | State | Overlay Of | In Service Date |
|---|---|---|---|
| 357 | CA | 559 | 26-Mar-2025 |
| 436 | OH | 440 | 01-Mar-2024 |
| 457 | LA | 318 | 25-Sep-2025 |
| 465 | NY | 718 | 18-Jun-2026 |
| 471 | MS | 662 | 30-Jan-2026 |
| 621 | TX | 713 | 23-Jan-2025 |
| 624 | NY | 716 | 16-Nov-2023 |
| 679 | MI | 313 | 07-Nov-2025 |
| 729 | TN | 423 | 05-Sep-2025 |
| 748 | CO | 970 | 07-Jul-2025 |
| 837 | CA | 530 | 31-Jan-2025 |
| 861 | IL | 309 | 24-Feb-2023 |
| 924 | MN | 507 | 30-Aug-2024 |
13 reserved area codes from the NANPA Area Code Database. These overlays have been assigned but no prefixes have been distributed yet.
What the Data Tells Us
Beyond the raw numbers, here are the patterns and insights our analysis reveals. Each conclusion is backed by verifiable data with methodology and source information.
Overlay growth has overtaken geographic splitting
Since 1947, 140 overlay area codes have been created versus 136 geographic splits. Since the 2010s, overlays have become the sole method of adding new area codes — the last geographic split was in the 2000s.
Key Evidence
- Total overlays created: 140
- Total splits created: 136
- Overlays became sole method: 2010s
- 2010s-2020s: 91 overlays, 0 splits
Utilization varies dramatically by state size
The highest average utilization rates are in small states with few area codes (e.g., Montana at 94.2%), while large states with many codes have lower averages. This reflects the mathematical reality that single-code states have no capacity to absorb demand spikes.
Key Evidence
- Top state by avg utilization: MT (94.2%)
- Bottom state by avg utilization: DC (53.4%)
- States with >90% avg utilization: 5
- Total area codes above 90% utilization: 158
Population density varies enormously across area codes
The population density across area codes spans more than four orders of magnitude (from 1 to 71917 people/sq mi). This extreme variation means a single area code can serve both dense urban cores and vast rural regions — a unique characteristic of the US numbering plan.
Key Evidence
- Minimum density: 1 people/sq mi
- Maximum density: 71917 people/sq mi
- Median density: 156 people/sq mi
- Area codes analyzed: 194
Income and area-code density are weakly correlated
There is a weak positive correlation (r = 0.185) between median household income and population density across area codes. While wealthier areas tend to be denser, the relationship is not strong enough to predict one from the other — other factors like telecom infrastructure and regulatory history play significant roles.
Key Evidence
- Pearson correlation (income vs density): 0.185
- Area codes analyzed: 194
- R-squared: 0.034 (only 3.4% of variance explained)
Area Code Utilization by State
Average utilization of area codes in each state. Higher values indicate closer to exhaustion.
Data as of Sep 8, 2026
Average area code utilization by state. Montana leads with 94.2% average utilization across 1 codes. 9 of 51 states/DC have average utilization above 80%, indicating potential future relief planning needs.
Splits vs Overlays Over Time
How area codes have been created since 1947 — by splitting existing codes or adding overlays.
Data as of Sep 8, 2026
From 1947 to 2026, 276 area codes were created: 136 by splits and 140 as overlays. Since 2000, overlays have dominated, with 122 overlays vs 31 splits.
Largest Area Code Family Trees
The original 1947 area codes that spawned the most descendants through splits and overlays.
Demographic Overview
Population, income, and education statistics across all US area codes.
Data as of Sep 8, 2026
Area Code Density by State
Number of area codes per million people. States with higher density need more codes.
Data as of Sep 8, 2026
Income vs Area Code Density
Relationship between median household income, population density, and area code allocation.
Data as of Sep 8, 2026