Key Findings
Every assignable prefix is assigned
In-service codes of the 50 states + DC with a utilization reading
All in-service codes, including 13 overlays with no prefixes assigned yet
92 of 372 in-service area codes have assigned every prefix NANPA can assign: no vacant prefix is left. They share rank 1, because ordering them further would only reflect how many prefixes each code holds as unavailable (13 to 51), not how exhausted it is. The next group has a single vacant prefix left (16 codes). When a code approaches exhaustion, NANPA begins relief planning, either an overlay or a split, to keep numbers available.
All Area Codes
Look up a specific area code's utilization ranking. Each row links directly to the area code's detail page.
| Rank | Area Code | Assigned of assignable |
|---|---|---|
| 1 | 202 | 100.0% |
| 1 | 203 | 100.0% |
| 1 | 205 | 100.0% |
| 1 | 208 | 100.0% |
| 1 | 209 | 100.0% |
| 1 | 210 | 100.0% |
| 1 | 212 | 100.0% |
| 1 | 213 | 100.0% |
| 1 | 214 | 100.0% |
| 1 | 215 | 100.0% |
| 1 | 217 | 100.0% |
| 1 | 240 | 100.0% |
| 1 | 248 | 100.0% |
| 1 | 256 | 100.0% |
| 1 | 267 | 100.0% |
| 1 | 281 | 100.0% |
| 1 | 301 | 100.0% |
| 1 | 303 | 100.0% |
| 1 | 304 | 100.0% |
| 1 | 310 | 100.0% |
| 1 | 314 | 100.0% |
| 1 | 315 | 100.0% |
| 1 | 317 | 100.0% |
| 1 | 323 | 100.0% |
| 1 | 330 | 100.0% |
| 1 | 334 | 100.0% |
| 1 | 336 | 100.0% |
| 1 | 347 | 100.0% |
| 1 | 360 | 100.0% |
| 1 | 402 | 100.0% |
| 1 | 404 | 100.0% |
| 1 | 405 | 100.0% |
| 1 | 407 | 100.0% |
| 1 | 408 | 100.0% |
| 1 | 410 | 100.0% |
| 1 | 415 | 100.0% |
| 1 | 419 | 100.0% |
| 1 | 443 | 100.0% |
| 1 | 469 | 100.0% |
| 1 | 470 | 100.0% |
| 1 | 484 | 100.0% |
| 1 | 503 | 100.0% |
| 1 | 510 | 100.0% |
| 1 | 512 | 100.0% |
| 1 | 516 | 100.0% |
| 1 | 518 | 100.0% |
| 1 | 540 | 100.0% |
| 1 | 561 | 100.0% |
| 1 | 573 | 100.0% |
| 1 | 601 | 100.0% |
| 1 | 609 | 100.0% |
| 1 | 610 | 100.0% |
| 1 | 617 | 100.0% |
| 1 | 618 | 100.0% |
| 1 | 630 | 100.0% |
| 1 | 646 | 100.0% |
| 1 | 678 | 100.0% |
| 1 | 702 | 100.0% |
| 1 | 703 | 100.0% |
| 1 | 704 | 100.0% |
| 1 | 706 | 100.0% |
| 1 | 707 | 100.0% |
| 1 | 713 | 100.0% |
| 1 | 714 | 100.0% |
| 1 | 717 | 100.0% |
| 1 | 718 | 100.0% |
| 1 | 720 | 100.0% |
| 1 | 740 | 100.0% |
| 1 | 757 | 100.0% |
| 1 | 760 | 100.0% |
| 1 | 786 | 100.0% |
| 1 | 803 | 100.0% |
| 1 | 804 | 100.0% |
| 1 | 805 | 100.0% |
| 1 | 812 | 100.0% |
| 1 | 813 | 100.0% |
| 1 | 814 | 100.0% |
| 1 | 815 | 100.0% |
| 1 | 816 | 100.0% |
| 1 | 832 | 100.0% |
| 1 | 843 | 100.0% |
| 1 | 845 | 100.0% |
| 1 | 864 | 100.0% |
| 1 | 870 | 100.0% |
| 1 | 903 | 100.0% |
| 1 | 904 | 100.0% |
| 1 | 909 | 100.0% |
| 1 | 910 | 100.0% |
| 1 | 916 | 100.0% |
| 1 | 917 | 100.0% |
| 1 | 919 | 100.0% |
| 1 | 972 | 100.0% |
| 93 | 201 | 99.9% |
| 93 | 305 | 99.9% |
| 93 | 312 | 99.9% |
| 93 | 513 | 99.9% |
| 93 | 608 | 99.9% |
| 93 | 615 | 99.9% |
| 93 | 619 | 99.9% |
| 93 | 631 | 99.9% |
| 93 | 715 | 99.9% |
| 93 | 724 | 99.9% |
| 93 | 732 | 99.9% |
| 93 | 773 | 99.9% |
| 93 | 847 | 99.9% |
| 93 | 850 | 99.9% |
| 93 | 860 | 99.9% |
| 93 | 918 | 99.9% |
| 109 | 309 | 99.8% |
| 109 | 770 | 99.8% |
| 109 | 801 | 99.8% |
| 109 | 920 | 99.8% |
| 109 | 480 | 99.7% |
| 109 | 530 | 99.7% |
| 109 | 570 | 99.7% |
| 109 | 817 | 99.7% |
| 109 | 508 | 99.7% |
| 118 | 614 | 99.6% |
| 118 | 708 | 99.6% |
| 118 | 937 | 99.6% |
| 118 | 973 | 99.6% |
| 122 | 541 | 99.5% |
| 122 | 559 | 99.5% |
| 122 | 978 | 99.5% |
| 125 | 818 | 99.4% |
| 125 | 781 | 99.3% |
| 127 | 954 | 98.7% |
| 128 | 970 | 98.2% |
| 129 | 270 | 98.0% |
| 130 | 716 | 97.8% |
| 130 | 412 | 97.8% |
| 132 | 313 | 97.7% |
| 133 | 318 | 97.3% |
| 134 | 423 | 97.1% |
| 134 | 507 | 97.1% |
| 134 | 509 | 97.1% |
| 137 | 440 | 96.4% |
| 138 | 662 | 96.3% |
| 139 | 206 | 96.2% |
| 140 | 406 | 95.9% |
| 140 | 603 | 95.9% |
| 142 | 602 | 95.3% |
| 142 | 701 | 95.3% |
| 142 | 207 | 95.3% |
| 145 | 580 | 95.0% |
| 146 | 605 | 94.8% |
| 147 | 346 | 94.7% |
| 148 | 949 | 94.5% |
| 149 | 502 | 93.8% |
| 150 | 806 | 93.7% |
Showing 150 of 372 area codes
Methodology
Data sources: Prefix utilization data from the NANPA NPA Exhaust Analysis report. Relief planning status from the NANPA NPA Relief Planning Reports.
Utilization %: Assigned prefixes / assignable prefixes × 100. Of the 800 NXX codes of an area code, 13 to 51 are unavailable by rule (N11 service codes and similar) and can never be assigned; they are left out of the denominator. Protected and reserved prefixes stay in it.
Ranking: Area codes are sorted by vacant prefixes remaining (fewest first). Codes with the same number of vacant prefixes share a rank; the 92 fully assigned codes are all rank 1.
Method change (2026-10-27): earlier versions divided by all 800 prefixes. That capped the maximum at about 98.4% and ordered the most exhausted codes by how many unavailable prefixes they happen to hold. Numbers published before this date (for example "highest utilization 98.4%") are superseded.
Not listed: the 3 codes assigned by NANPA but not yet in service (see the Statistics page). The 13 overlays that are in service but have no prefixes assigned yet are listed with 0%.
Last updated: October 27, 2026
Embed This Data
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Exhaustion Ranking Widget
<iframe
src="https://aclookup.com/embed/exhaustion-ranking"
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style="border:0;border-radius:8px"
loading="lazy"
title="Area Code Data Widget — aclookup.com"
></iframe>
<p style="font-size:12px;color:#666;margin-top:4px">
Data: <a href="https://aclookup.com/studies/" target="_blank" rel="noopener">aclookup.com</a>
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