Area codes 617 and 857 are telephone area codes in the North American Numbering Plan (NANP) for the U.S. state of Massachusetts, serving the city of Boston and several surrounding communities such as Brookline, Cambridge, Newton and Quincy. Area code 617 is one of the original North American area codes created in October 1947, when it served the eastern two-thirds of Massachusetts, from roughly the western end of Worcester County to Cape Cod and the South Coast.

History 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 October 2025, the 617/857 NPA is projected to be exhausted by 2059.October 2025 NPA Exhaust Analysis

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

Essex Middlesex Norfolk Suffolk

This includes the following communities:

Belmont Boston Brookline Cambridge Chelsea Everett Milton Newton Quincy Somerville Watertown Winthrop

Central office codes by location The NPA includes central offices with the following prefix format 617-NXX: 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

N11 codes

2-1-1: United Way Worldwide (UWW) and the Alliance for Information and Referral Systems (AIRS) 3-1-1: Used in Newton, Boston, and elsewhereOperational Services Brief: 311 in Massachusetts, Edward J. Collins Center for Public Management Publications, 10-24-2008 for 3-1-1 services. 4-1-1: directory assistance 5-1-1: traffic information or police non-emergency services511 Massachusetts 6-1-1: unused (on landlines) 7-1-1: TDD relay (MassRelay) for the deafMass Relay 8-1-1: underground public utility location (Dig Safe),Dig SafeFCC Doc. No. 92-105 9-1-1: emergency services

See also List of Massachusetts area codes List of North American Numbering Plan area codes

References

External links

Massachusetts Area Code Map, Mass. Department of Telecommunications and Cable