Area codes 617 and 857

Massachusetts was the only New England state divided into multiple numbering plan areas (NPAs) when the American Telephone and Telegraph Company (AT&T) devised the first nationwide telephone numbering plan in 1947. Area code 617 was assigned to the more populous eastern portion, stretching from roughly the western end of Worcester County to Cape Cod and the South Coast. The rest of the state, roughly everything from Hardwick westward, was served by area code 413.

In July 1988, most of the western, northern, and southern portions of the old 617 territory, including Worcester County, the Merrimack Valley, the South Coast, and the Cape and Islands, were split off as area code 508. Permissive dialing of 617 continued across eastern Massachusetts until January 1, 1989.

In 1997, the northern, western and southern portions of the new 617 split off as 781, which almost completely surrounds 617. This made 617 largely coextensive with the inner ring of Greater Boston.

This was intended as a long-term solution, but within three years 617 was close to exhaustion once again due to the demand for more phone lines for auxiliary devices (mobile phones, fax machines, pagers, and BBS lines). On May 2, 2001, 857 was overlaid onto 617. Since then, 10-digit local dialing has been mandatory.

Some mobile telephone numbers from the 1990s assigned to communities in the area surrounding 617 (which is now the 781 area code) kept the 617 area code after the split.

Area code 508 was split from 617 on July 16, 1988. Area code 978 subsequently split from 508 on September 1, 1997.

Area code 781 was split from 617 on September 1, 1997.

As of 2018, the 617/857 NPA is projected to be exhausted by 2041.[1]

The numbering plan area 617/857 includes portions of the following counties:

This includes the following communities:

The NPA includes central offices with the following prefix format 617-NXX:[2][3][4]

• Belmont: 209, 404, 484, 486, 489, 672, 826, 855, 883, 932, 977, 993
• Boston Central: 204, 205, 210, 212, 217, 222, 223, 224, 226, 227, 228, 235, 236, 239, 246, 247, 248, 255, 259, 261, 262, 263, 266, 267, 275, 279, 283, 289, 292, 293, 295, 303, 304, 305, 306, 309, 310, 312, 314, 316, 320, 330, 331, 338, 341, 342, 343, 345, 346, 348, 350, 351, 352, 353, 356, 357, 358, 366, 367, 368, 369, 371, 372, 373, 375, 377, 378, 385, 391, 392, 399, 406, 407, 412, 413, 414, 416, 421, 422, 423, 424, 425, 426, 428, 429, 434, 437, 438, 439, 443, 447, 448, 449, 450, 451, 456, 457, 459, 470, 476, 478, 480, 482, 488, 490, 502, 504, 507, 510, 512, 513, 515, 517, 519, 521, 523, 526, 530, 531, 532, 534, 535, 536, 542, 543, 549, 556, 557, 563, 565, 570, 571, 572, 573, 574, 578, 579, 585, 587, 589, 590, 592, 593, 594, 595, 598, 603, 619, 620, 624, 626, 635, 636, 637, 638, 643, 645, 646, 648, 650, 654, 662, 664, 670, 671, 672, 680, 683, 686, 692, 694, 695, 697, 699, 717, 719, 720, 721, 722, 723, 724, 725, 726, 727, 728, 733, 737, 742, 743, 747, 748, 753, 755, 756, 757, 760, 763, 772, 777, 778, 780, 784, 785, 788, 790, 794, 799, 816, 818, 820, 823, 824, 828, 830, 832, 834, 835, 838, 839, 840, 848, 849, 850, 851, 854, 856, 859, 861, 865, 867, 869, 872, 875, 877, 878, 880, 888, 892, 894, 896, 897, 901, 904, 908, 912, 918, 919, 921, 927, 931, 933, 936, 937, 938, 939, 943, 946, 947, 948, 951, 954, 956, 959, 960, 961, 963, 973, 986, 988, 989, 994
• Brighton: 202, 206, 208, 254, 300, 319, 403, 415, 560, 562, 586, 746, 779, 782, 783, 787, 789, 817, 870, 891, 903, 925, 987
• Brookline: 232, 264, 274, 277, 278, 355, 383, 396, 432, 487, 505, 525, 566, 582, 608, 632, 651, 667, 677, 713, 730, 731, 732, 734, 735, 738, 739, 751, 754, 860, 879, 906, 935, 953, 975, 991, 992
• Cambridge: 201, 216, 218, 225, 229, 230, 233, 234, 245, 250, 251, 252, 253, 256, 258, 280, 290, 299, 301, 308, 324, 335, 339, 349, 354, 359, 374, 384, 386, 388, 395, 397, 401, 417, 430, 441, 444, 452, 453, 460, 465, 468, 475, 491, 492, 493, 494, 495, 496, 497, 498, 499, 500, 503, 520, 528, 540, 547, 550, 551, 575, 576, 577, 583, 588, 599, 613, 621, 642, 647, 649, 661, 665, 674, 679, 682, 685, 693, 703, 710, 714, 715, 758, 761, 768, 798, 800, 802, 803, 806, 812, 821, 836, 844, 852, 858, 864, 866, 868, 871, 873, 876, 899, 902, 909, 914, 940, 945, 949, 955, 976, 995, 998, 999
• Charlestown: 241, 242, 286, 337, 380, 398, 580, 669, 681, 712, 886, 952, 982
• Chelsea: 270, 336, 370, 409, 461, 466, 660, 819, 884, 887, 889, 958
• Dorchester: 265, 282, 287, 288, 297, 326, 379, 436, 446, 474, 506, 514, 533, 704, 707, 740, 822, 825, 905, 929, 979
• East Boston: 271, 418, 455, 561, 567, 568, 569, 634, 716, 874, 895, 913, 970, 981, 997
• Everett: 203, 294, 381, 382, 387, 389, 394, 410, 420, 544, 545, 601, 843, 917, 944
• Hyde Park (includes Readville and parts of Milton): 214, 272, 276, 333, 360, 361, 362, 364, 408, 604, 675, 705, 833, 910, 990
• Jamaica Plain (includes Roslindale and West Roxbury): 323, 325, 327, 344, 363, 390, 435, 469, 477, 522, 524, 553, 676, 942, 971, 983
• Melrose: 957
• Milton (includes Mattapan; see also Hyde Park): 273, 291, 296, 298, 313, 322, 433, 615, 690, 696, 698, 898, 907, 915, 922, 980
• Newton: 213, 215, 219, 243, 244, 332, 340, 431, 454, 467, 473, 485, 527, 546, 552, 558, 559, 564, 581, 584, 597, 609, 610, 614, 618, 630, 631, 641, 644, 655, 656, 658, 659, 663, 678, 762, 775, 795, 796, 831, 853, 862, 881, 882, 885, 893, 916, 928, 964, 965, 969
• Quincy: 221, 237, 249, 302, 317, 328, 347, 376, 405, 471, 472, 479, 481, 483, 509, 537, 639, 653, 657, 687, 689, 691, 706, 729, 745, 750, 769, 770, 773, 774, 786, 793, 801, 804, 829, 837, 842, 845, 847, 890, 934, 984, 985
• Roxbury: 238, 318, 400, 427, 442, 445, 516, 541, 602, 606, 652, 708, 749, 792, 989
• Saugus: 285
• Somerville: 284, 440, 501, 591, 616, 623, 625, 627, 628, 629, 666, 684, 702, 718, 741, 764, 767, 776, 863, 941, 996
• South Boston: 268, 269, 307, 315, 334, 463, 464, 596, 622, 701, 752, 765, 766
• Watertown: 231, 321, 393, 402, 458, 600, 607, 612, 668, 673, 744, 923, 924, 926, 972
• Winthrop: 207, 329, 539, 841, 846

The NPA includes central offices with the following prefix format 857-NXX:

• Belmont: 373, 626
• Boston Central: 201, 204, 205, 207, 221, 222, 238, 241, 254, 257, 272, 277, 284, 288, 294, 319, 334, 350, 355, 362, 366, 383, 413, 445, 449, 453, 472, 488, 654, 753, 869, 891, 931, 991, 996
• Brighton: 498, 540, 559, 919
• Brookline: 218, 225, 234, 245, 307, 364, 576
• Cambridge: 209, 253, 550, 600, 756, 829, 928, 940, 976, 998
• Charlestown: 389, 452, 588
• Chelsea: 776
• Dorchester: 212, 217, 220
• East Boston: 574
• Everett: 363, 888
• Hyde Park: 342, 345
• Jamaica Plain: 203, 547, 719, 728
• Milton: 598
• Newton: 226, 229, 231, 232, 255, 404, 636
• Quincy: 252, 403, 499, 526, 939
• Roxbury: 399, 492, 544
• Somerville: 227, 523, 995, 997
• South Boston: 401, 496, 524
• Watertown: 228
• Winthrop: 201, 816

• 2-1-1: United Way Worldwide (UWW) and the Alliance for Information and Referral Systems (AIRS)
• 3-1-1: Used in Newton, Boston, and elsewhere[5] for 3-1-1 services.
• 4-1-1: directory assistance
• 5-1-1: traffic information or police non-emergency services[6]
• 6-1-1: unused (on landlines)
• 7-1-1: TDD relay (MassRelay) for the deaf[7]
• 8-1-1: underground public utility location (Dig Safe),[8][9]
• 9-1-1: emergency services

• List of Massachusetts area codes
• List of North American Numbering Plan area codes

• NANPA area code map of Massachusetts
• Massachusetts Area Code Map, Mass. Department of Telecommunications and Cable
• NANP Administrator (July 2, 1987). "Split of the 617 Numbering Plan Area (NPA)" (PDF). www.nationalnanpa.com. IL-87/07-003. NANP Administrator. Retrieved January 11, 2023. Provides notification of date for the split of the 617 NPA and introduction of the new 508 NPA in Massachusetts.{{cite web}}: CS1 maint: date and year (link)
• Staff writer (2023) [2005]. "Area Code 617 map and data profile". Area-Codes.com. Retrieved January 12, 2023. Area Code 617 Demographic Information
• "Local Calling Guide". localcallingguide.com. 2023. Retrieved January 12, 2023.
• Staff writer (2023). "Area Code, Exchange, Telco, Switch info in 617". telcodata.us. Retrieved January 12, 2023.