| Overlay area codes | Location | Notes |
|---|
| Added | Base |
|---|
| 557 | 314 | St. Louis, Missouri (communities such as, but not limited to, St. Louis, Overland, Bridgeton, Florissant, Webster Groves, Creve Coeur, Kirkwood and Sappington) | Initial overlay area code plan was announced October 24, 2000. New 557 area code was announced in February 2022 and went into effect August 12, 2022. |
| 324 | 904 | Jacksonville, Jacksonville Beach, Fernandina Beach, Orange Park and surrounding communities | |
| 220 | 740 | Central and southeastern Ohio | |
| 223 | 717 | South Central Pennsylvania | |
| 224 | 847 | Northern suburbs of Chicago, Illinois | |
| 226, 382, 548 | 519 | Southwestern Ontario | |
| 234 | 330 | Akron-Canton and Warren-Youngstown areas in Ohio | |
| 236, 672, 778 | 604, 250 | British Columbia | |
| 227, 240 | 301 | Washington, D.C. suburbs and panhandle of Maryland | |
| 249 | 705 | Northeastern and central Ontario | |
| 267, 445 | 215 | Philadelphia, Pennsylvania area and a small portion of its Pennsylvania suburbs | |
| 272 | 570 | Northeastern Pennsylvania, including the cities of Scranton, Wilkes-Barre, and Williamsport | |
| 279 | 916 | Sacramento, California and surrounding suburbs | |
| 281, 346, 621, 832 | 713 | Greater Houston, Texas | |
| 289, 365 | 905 | Golden Horseshoe region of Ontario, including suburban Toronto, Hamilton, Oshawa, and the Niagara Peninsula in Ontario | |
| 321 | 407 | Central Florida | In addition to being the sole area code in the Space Coast region around the Kennedy Space Center, this is the only partial overlay area code in North America |
| 323 | 213 | Central Los Angeles, incl. Downtown L.A. and Hollywood | |
| 326 | 937 | Southwest Ohio | |
| 331 | 630 | Western suburbs of Chicago | |
| 332, 646 , 917 | 212 | New York City borough of Manhattan, except for the Marble Hill neighborhood, which is physically connected to The Bronx and uses 718 | |
| 339 | 781 | Suburban Boston, Massachusetts and most of the South Shore region | |
| 341 | 510 | San Francisco East Bay | |
| 343 | 613 | Ottawa and eastern Ontario | |
| 347, 929 | 718 | New York City boroughs of The Bronx, Brooklyn, Queens, and Staten Island, as well as Marble Hill, a Manhattan neighborhood directly connected to The Bronx [2] | |
| 351 | 978 | North-central and most of northeastern Massachusetts | |
| 364 | 270 | Western half of Kentucky, including the Purchase area, the Western Coal Fields, and most of the Pennyrile [3] | |
| 367, 581 | 418 | Eastern Quebec | |
| 368, 587, 825 | 780, 403 | Alberta | |
| 380 | 614 | Columbus, Ohio, and suburbs | |
| 385 | 801 | Along the Wasatch Front of Utah, including Salt Lake City, Provo–Orem, and Ogden | |
| 424 | 310 | Southwestern Los Angeles County, California | |
| 430 | 903 | Northeastern Texas | |
| 431 | 204 | Manitoba | |
| 437, 647 | 416 | Toronto, Ontario | |
| 438 | 514 | Island of Montreal, Quebec | |
| 442 | 760 | Southeastern California | |
| 443, 667 | 410 | Baltimore metropolitan area and the Eastern Shore of Maryland | |
| 447 | 217 | Central Illinois | |
| 448 | 850 | Florida Panhandle, including Tallahassee and Pensacola | |
| 458 | 541 | Most of Oregon, excluding its northwestern part | |
| 464 | 708 | Near western suburbs and southern suburbs of Chicago | |
| 469, 972 | 214 | Eastern portion of the Dallas–Fort Worth metroplex in and around Dallas, Texas | |
| 470, 678 | 404, 770 | Atlanta metropolitan area, Georgia | |
| 474 | 306 | Saskatchewan | |
| 475 | 203 | Southwestern Connecticut | |
| 484 | 610 | Eastern and parts of southeastern Pennsylvania | |
| 531 | 402 | Eastern Nebraska | |
| 534 | 715 | Northern Wisconsin | |
| 539 | 918 | Northeastern Oklahoma | |
| 551 | 201 | Northeastern New Jersey | |
| 564 | 360 | Western Washington | 564 initially overlays only 360, but will expand to overlay 206, 253, and 425 as those area codes run out of numbers [4] |
| 567 | 419 | Northwestern Ohio, including Toledo and Lima | |
| 571 | 703 | Northern Virginia | |
| 572 | 405 | Central Oklahoma, including greater Oklahoma City | |
| 582 | 814 | Central and western Pennsylvania, including Altoona, DuBois, and Erie | |
| 587 | 403, 780 | Alberta | |
| 628 | 415 | San Francisco, Marin County and small portions of San Mateo County | |
| 629 | 615 | Nashville, Tennessee | |
| 639 | 306 | Saskatchewan | |
| 640 | 609 | Central and southeast New Jersey | |
| 657 | 714 | Northern Orange County, California | |
| 658 | 876 | Jamaica | |
| 659 | 205 | Western and central Alabama | |
| 669 | 408 | Southern Bay Area in California, encompassing much of Santa Clara County and Silicon Valley [5] | |
| 672 | 604, 250 | British Columbia | |
| 680 | 315 | An area of Upstate New York including parts of Central New York and the North Country, with Syracuse as the main city in the region | |
| 681 | 304 | West Virginia | |
| 682 | 817 | Western part of the Dallas–Fort Worth metroplex, in and around Fort Worth, Texas | |
| 689 | 407 | Orlando, Florida | |
| 720, 983 | 303 | Denver metropolitan area, Colorado | |
| 725 | 702 | Clark County, Nevada | |
| 726 | 210 | San Antonio, Texas | |
| 737 | 512 | Austin, Texas | |
| 743 | 336 | Piedmont Triad, North Carolina including Greensboro, Winston-Salem, and western areas of the Raleigh-Durham metropolitan area. | |
| 747 | 818 | San Fernando Valley, California | |
| 754 | 954 | Broward County, Florida | |
| 769 | 601 | Central Mississippi | |
| 771 | 202 | Washington, D.C. | |
| 774 | 508 | South-central and most of southeastern Massachusetts, including Cape Cod and the Islands | |
| 779 | 815 | Northern and north-central Illinois, including the Rockford, Freeport, and Kankakee areas | |
| 782 | 902 | Nova Scotia and Prince Edward Island on 30 November 2014 | |
| 786, 645 | 305 | Miami-Dade County, Florida and the Florida Keys | |
| 801 | 385 | Salt Lake City | |
| 820 | 805 | Ventura, Santa Barbara and San Luis Obispo Counties in California | |
| 825 | 403, 780 | Alberta | |
| 829, 849 | 809 | Dominican Republic | |
| 839 | 803 | Central South Carolina | |
| 840 | 909 | Pomona Valley and western San Bernardino County, CA | |
| 848 | 732 | Central New Jersey | |
| 857 | 617 | Boston, Cambridge and Quincy, Massachusetts | |
| 858 | 619 | San Diego, CA and surrounding area | |
| 862 | 973 | Northern New Jersey | |
| 872 | 312, 773 | Chicago, Illinois | |
| 873 | 819 | Gatineau and western Quebec | |
| 878 | 412, 724 | Metro Pittsburgh, Pennsylvania | |
| 917 | 212, 332, 347, 646, 718, 929 | The entirety of New York City (The Bronx, Brooklyn, Manhattan, Queens, and Staten Island) | Originally primarily for cellular phones and pagers [2] |
| 930 | 812 | Southern Indiana | |
| 934 | 631 | Suffolk County, New York | |
| 938 | 256 | Northern Alabama | |
| 939 | 787 | Puerto Rico | |
| 469, 972, 945 | 214 | Eastern greater Dallas-Fort Worth, TX | |
| 947 | 248 | Oakland County, Michigan | |
| 959 | 860 | Northern and western Connecticut | |
| 971 | 503 | Northwestern Oregon, including the Portland, Salem, and Astoria metropolitan areas | |
| 980 | 704 | Charlotte metropolitan area, North Carolina | |
| 984 | 919 | Raleigh-Durham, North Carolina metropolitan area | |
| 986 | 208 | Idaho | |
