Information for Area Code: 240-xxx-xxxx - MD - MARYLAND

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Information about Area Code 240

The blue area is Maryland; the red area is area codes 240 and 301

North American area codes 240 and 301 are state of Maryland telephone area codes which serve Maryland's portion of the Greater Washington, D.C. metro area, portions of Southern Maryland, and all points northwest of Washington. This includes the communities of Cumberland, Frederick, Hagerstown, and Rockville. Area code 301 was one of the original area codes established in 1947, and was the exclusive area code for the entire state of Maryland until it was split with 410 on October 6, 1991. The overlay area code, 240, was introduced on June 1, 1997.

Counties served by these area codes include:

local calls require 10-digit dialing (area code + number, leading "1" is not required)


State of Maryland Area Codes: 240, 301, 410, 443
North: 717, 724/878, 814
West: 202, 304, 540, 571/703 area codes 301/240 East: 410/443
South: 804, 304
District of Columbia Area Code: 202
Commonwealth of Pennsylvania Area Codes: 215, 267, 412, 484, 570, 610, 717, 724, 814, 835, 878
Commonwealth of Virginia Area Codes: 276, 434, 540, 571/703, 757, 804
State of West Virginia Area Code: 304


See also


Exchanges for Area Code 240-xxx-xxxx:

Exchange 240-201
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-205
- SOUTHWESTERN BELL MOBILE SYSTEMS, LLC - DC

Exchange 240-206
Washington - XO MARYLAND, LLC

Exchange 240-207
Washington - CAVALIER EAST LLC - MD

Exchange 240-208
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-209
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-210
Greenbelt - SOUTHWESTERN BELL MOBILE SYSTEMS, LLC - DC

Exchange 240-211
-

Exchange 240-212
MOUNT AIRY - CORE COMMUNICATIONS, INC. - MD

Exchange 240-213
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-214
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-215
Ijamsville - ADELPHIA BUSINESS SOLUTIONS OF MARYLAND, LLC

Exchange 240-216
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-217
Frederick - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-218
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-219
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-220
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-221
Rockville - VERIZON MARYLAND, INC.

Exchange 240-222
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-223
WASHINGTON - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-224
Alexandria - METROCALL

Exchange 240-225
MOUNT AIRY - CORE COMMUNICATIONS, INC. - MD

Exchange 240-226
-

Exchange 240-227
-

Exchange 240-228
Laurel - VERIZON MARYLAND, INC.

Exchange 240-229
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-230
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-231
MOUNT AIRY - CORE COMMUNICATIONS, INC. - MD

Exchange 240-232
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-233
Washington - TELEPORT COMMUNICATIONS GROUP, INC. - DC

Exchange 240-234
Savage - ARCH WIRELESS HOLDINGS, INC.

Exchange 240-235
Chevy Chase - PAETEC COMMUNICATIONS, INC. - MD

Exchange 240-236
Frederick - VERIZON MARYLAND, INC.

Exchange 240-237
Washington - TELEPORT COMMUNICATIONS GROUP, INC. - DC

Exchange 240-238
Chevy Chase - PAETEC COMMUNICATIONS, INC. - MD

Exchange 240-239
Damascus - CORE COMMUNICATIONS, INC. - MD

Exchange 240-240
-

Exchange 240-241
Lanham - STARPOWER COMMUNICATIONS, LLC - MD

Exchange 240-242
Lanham - STARPOWER COMMUNICATIONS, LLC - MD

Exchange 240-243
WASHINGTON - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-244
Lanham - STARPOWER COMMUNICATIONS, LLC - MD

Exchange 240-245
Lanham - STARPOWER COMMUNICATIONS, LLC - MD

Exchange 240-246
Lanham - STARPOWER COMMUNICATIONS, LLC - MD

Exchange 240-247
WASHINGTON - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-248
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-249
Washington - TELEPORT COMMUNICATIONS GROUP, INC. - DC

Exchange 240-250
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-251
MOUNT AIRY - CORE COMMUNICATIONS, INC. - MD

Exchange 240-252
RESTON - LEVEL 3 COMMUNICATIONS, LLC - MD

Exchange 240-253
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-254
Washington - TELEPORT COMMUNICATIONS GROUP, INC. - DC

Exchange 240-255
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-256
Washington - TELEPORT COMMUNICATIONS GROUP, INC. - DC

Exchange 240-257
Washington - TELEPORT COMMUNICATIONS GROUP, INC. - DC

Exchange 240-258
Washington - TELEPORT COMMUNICATIONS GROUP, INC. - DC

Exchange 240-259
-

Exchange 240-260
WASHINGTON - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-261
Reston - GLOBAL NAPS, INC.-MA

Exchange 240-262
- TIDALWAVE TELEPHONE INC.

Exchange 240-263
Chantilly - TIDALWAVE TELEPHONE INC.

Exchange 240-264
Beltsville - VERIZON MARYLAND, INC.

Exchange 240-265
Chantilly - TIDALWAVE TELEPHONE INC.

Exchange 240-266
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-267
Chantilly - TIDALWAVE TELEPHONE INC.

Exchange 240-268
WASHINGTON - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-269
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-270
Chantilly - TIDALWAVE TELEPHONE INC.

Exchange 240-271
Greenbelt - SOUTHWESTERN BELL MOBILE SYSTEMS, LLC - DC

Exchange 240-272
Chantilly - TIDALWAVE TELEPHONE INC.

Exchange 240-273
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-274
Greenbelt - SOUTHWESTERN BELL MOBILE SYSTEMS, LLC - DC

Exchange 240-275
MOUNT AIRY - CORE COMMUNICATIONS, INC. - MD

Exchange 240-276
Gaithersburg - VERIZON MARYLAND, INC.

Exchange 240-277
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-279
Damascus - CORE COMMUNICATIONS, INC. - MD

Exchange 240-280
Chevy Chase - COMCAST BUSINESS COMMUNICATIONS, INC. - MD

Exchange 240-281
Greenbelt - SOUTHWESTERN BELL MOBILE SYSTEMS, LLC - DC

Exchange 240-282
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-283
Chevy Chase - PAETEC COMMUNICATIONS, INC. - MD

Exchange 240-284
Frederick - NATIONSLINE, INC.-MD

Exchange 240-285
- CAVALIER EAST LLC - MD

Exchange 240-286
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-287
MOUNT AIRY - CORE COMMUNICATIONS, INC. - MD

Exchange 240-288
Frederick - NATIONSLINE, INC.-MD

Exchange 240-289
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-290
WASHINGTON - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-291
Monrovia - AT&T WIRELESS SERVICES, INC.

Exchange 240-292
Silver Spring - VERIZON MARYLAND, INC.

Exchange 240-293
Lanham - STARPOWER COMMUNICATIONS, LLC - MD

Exchange 240-294
Washington - XO MARYLAND, LLC

Exchange 240-295
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-296
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-297
RESTON - LEVEL 3 COMMUNICATIONS, LLC - MD

Exchange 240-298
Washington - CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD

Exchange 240-299
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-301
-

Exchange 240-303
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-304
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-305
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-306
WASHINGTON - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-307
Monrovia - AT&T LOCAL

Exchange 240-308
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-310
Cumberland - USCOC OF CUMBERLAND, INC. DBA UNITED STATES CEL MD

Exchange 240-311
-

Exchange 240-312
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-313
Hagerstown - VERIZON MARYLAND, INC.

Exchange 240-314
Rockville - VERIZON MARYLAND, INC.

Exchange 240-315
Frederick - VERIZON MARYLAND, INC.

Exchange 240-317
Lanham - STARPOWER COMMUNICATIONS, LLC - MD

Exchange 240-318
Clinton - VERIZON MARYLAND, INC.

Exchange 240-320
Washington - CAVALIER EAST LLC - MD

Exchange 240-321
CUMBERLAND - USCOC OF CUMBERLAND, INC. DBA UNITED STATES CEL MD

Exchange 240-322
MOUNT AIRY - CORE COMMUNICATIONS, INC. - MD

Exchange 240-323
MOUNT AIRY - CORE COMMUNICATIONS, INC. - MD

Exchange 240-325
Damascus - CORE COMMUNICATIONS, INC. - MD

Exchange 240-326
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-327
Damascus - CORE COMMUNICATIONS, INC. - MD

Exchange 240-328
Rockville - VERIZON MARYLAND, INC.

Exchange 240-329
Frederick - LEVEL 3 COMMUNICATIONS, LLC - MD

Exchange 240-331
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-332
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-333
Washington - CAVALIER EAST LLC - MD

Exchange 240-334
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-335
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-336
Damascus - CORE COMMUNICATIONS, INC. - MD

Exchange 240-337
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-338
Annapolis Junction - CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD

Exchange 240-339
Washington - CAVALIER EAST LLC - MD

Exchange 240-342
Lanham - STARPOWER COMMUNICATIONS, LLC - MD

Exchange 240-344
Monrovia - AT&T WIRELESS SERVICES, INC.

Exchange 240-345
Pikesville -

Exchange 240-346
Washington - SPRINT SPECTRUM L.P.

Exchange 240-348
RESTON - LEVEL 3 COMMUNICATIONS, LLC - MD

Exchange 240-349
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-350
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-351
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-352
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-353
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-354
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-355
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-356
Frederick - LEVEL 3 COMMUNICATIONS, LLC - MD

Exchange 240-357
FREDERICK -

Exchange 240-358
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-359
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-361
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-362
CRESAPTOWN - VERIZON MARYLAND, INC.

Exchange 240-363
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-364
Washington - CAVALIER EAST LLC - MD

Exchange 240-365
Laurel - BALTIMORE-WASHINGTON TELEPHONE BWT

Exchange 240-366
Monrovia - AT&T LOCAL

Exchange 240-367
Frederick - NEXTEL COMMUNICATIONS

Exchange 240-368
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-369
MOUNT AIRY - CORE COMMUNICATIONS, INC. - MD

Exchange 240-371
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-372
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-373
ODENTON - VERIZON MARYLAND, INC.

Exchange 240-374
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-375
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-376
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-377
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-378
MOUNT AIRY - CORE COMMUNICATIONS, INC. - MD

Exchange 240-379
Frederick - VERIZON MARYLAND, INC.

Exchange 240-381
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-383
Greenbelt - SOUTHWESTERN BELL MOBILE SYSTEMS, LLC - DC

Exchange 240-384
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-385
MYERSVILLE - VERIZON MARYLAND, INC.

Exchange 240-386
Gaithersburg - VERIZON MARYLAND, INC.

Exchange 240-387
Washington - CAVALIER EAST LLC - MD

Exchange 240-388
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-389
WASHINGTON - ATX TELECOMMUNICATIONS SERVICES, LTD

Exchange 240-390
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-391
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-392
Lanham - STARPOWER COMMUNICATIONS, LLC - MD

Exchange 240-393
Annapolis Junction - CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD

Exchange 240-394
Frederick - SOUTHWESTERN BELL MOBILE SYSTEMS, LLC - DC

Exchange 240-395
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-396
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-398
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-399
Washington - XO MARYLAND, LLC

Exchange 240-401
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-403
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-404
Washington - XO MARYLAND, LLC

Exchange 240-405
Frederick - US LEC OF MARYLAND, INC.

Exchange 240-407
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-409
Frederick - DOBSON CELLULAR SYSTEMS, INC.

Exchange 240-410
-

Exchange 240-411
-

Exchange 240-412
Washington - SPRINT SPECTRUM L.P.

Exchange 240-413
Beltsville - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-414
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-416
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-417
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-418
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-420
Hagerstown - VERIZON MARYLAND, INC.

Exchange 240-421
Beltsville - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-422
Frederick - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-423
Beltsville - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-425
Vienna - TALKINGNETS HOLDINGS, LLC - MD

Exchange 240-426
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-427
Washington - XO MARYLAND, LLC

Exchange 240-429
Adelphi -

Exchange 240-430
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-431
Washington - SPRINT SPECTRUM L.P.

Exchange 240-432
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-433
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-434
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-436
Ijamsville - ADELPHIA BUSINESS SOLUTIONS OF MARYLAND, LLC

Exchange 240-437
Washington - XO MARYLAND, LLC

Exchange 240-441
Beltsville - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-442
THAYERVILLE - KMC TELECOM V, INC. - MD

Exchange 240-443
-

Exchange 240-446
FREDERICK - CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD

Exchange 240-447
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-449
Greenbelt - SOUTHWESTERN BELL MOBILE SYSTEMS, LLC - DC

Exchange 240-450
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-453
Rockville - VERIZON MARYLAND, INC.

Exchange 240-454
Chevy Chase - SOUTHWESTERN BELL MOBILE SYSTEMS, LLC - DC

Exchange 240-455
Sterling - PAETEC COMMUNICATIONS, INC. - DC

Exchange 240-456
Laurel - VERIZON MARYLAND, INC.

Exchange 240-460
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-461
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-462
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-463
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-464
Silver Spring - MCI WORLDCOM COMMUNICATIONS, INC. - MD

Exchange 240-465
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-466
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-471
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-472
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-473
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-475
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-476
Beltsville - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-477
- LIGHTWAVE COMMUNICATIONS, LLC - MD

Exchange 240-478
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-481
Beltsville - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-482
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-483
Baltimore - COMCAST BUSINESS COMMUNICATIONS, INC. - MD

Exchange 240-485
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-486
Beltsville - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-487
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-489
Washington - XO MARYLAND, LLC

Exchange 240-490
Frederick - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-491
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-492
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-493
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-494
Washington - CAVALIER EAST LLC - MD

Exchange 240-497
Chevy Chase - VERIZON MARYLAND, INC.

Exchange 240-498
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-499
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-501
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-505
Beltsville - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-506
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-508
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-510
Washington - XO MARYLAND, LLC

Exchange 240-511
-

Exchange 240-512
Pikesville -

Exchange 240-514
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-515
Greenbelt - SOUTHWESTERN BELL MOBILE SYSTEMS, LLC - DC

Exchange 240-516
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-520
Hagerstown -

Exchange 240-522
Cumberland - SPRINT SPECTRUM L.P. - MD

Exchange 240-523
Washington - XO MARYLAND, LLC

Exchange 240-524
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-525
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-526
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-527
Hagerstown - VERIZON MARYLAND, INC.

Exchange 240-528
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-529
Frederick - VERIZON MARYLAND, INC.

Exchange 240-533
Washington - TELEPORT COMMUNICATIONS GROUP, INC. - DC

Exchange 240-535
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-536
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-538
Washington - XO MARYLAND, LLC

Exchange 240-539
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-542
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-543
Beltsville -

Exchange 240-544
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-545
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-546
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-547
RESTON - LEVEL 3 COMMUNICATIONS, LLC - MD

Exchange 240-548
WASHINGTON - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-553
WASHINGTON - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-554
WASHINGTON - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-555
Baltimore - VERIZON MARYLAND, INC.

Exchange 240-556
Chevy Chase - PAETEC COMMUNICATIONS, INC. - MD

Exchange 240-558
HERNDON - CAVALIER TELEPHONE MID-ATLANTIC. LLC - MD

Exchange 240-559
WASHINGTON - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-560
Washington - XO MARYLAND, LLC

Exchange 240-565
Baltimore -

Exchange 240-566
Frederick - VERIZON MARYLAND, INC.

Exchange 240-567
Rockville -

Exchange 240-568
Laurel - VERIZON MARYLAND, INC.

Exchange 240-571
-

Exchange 240-573
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-575
Frederick -

Exchange 240-577
Washington -

Exchange 240-580
Cumberland - NEXTEL PARTNERS OPERATING CORP.

Exchange 240-581
Washington - PAETEC COMMUNICATIONS, INC. - DC

Exchange 240-582
Hyattsville - VERIZON MARYLAND, INC.

Exchange 240-586
Frederick -

Exchange 240-593
Baltimore - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-595
Adelphi -

Exchange 240-597
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-599
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-600
Frederick -

Exchange 240-601
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-602
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-603
- SPRINT SPECTRUM L.P.

Exchange 240-604
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-605
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-606
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-607
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-611
-

Exchange 240-616
RESTON - MCI WORLDCOM COMMUNICATIONS, INC. - MD

Exchange 240-619
RESTON - MCI WORLDCOM COMMUNICATIONS, INC. - MD

Exchange 240-620
RESTON - MCI WORLDCOM COMMUNICATIONS, INC. - MD

Exchange 240-621
RESTON - MCI WORLDCOM COMMUNICATIONS, INC. - MD

Exchange 240-624
COLLEGE PARK - VERIZON MARYLAND, INC.

Exchange 240-625
Frederick - NEXTEL COMMUNICATIONS

Exchange 240-626
Hagerstown - SPRINT SPECTRUM L.P.

Exchange 240-627
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-629
Frederick - VERIZON MARYLAND, INC.

Exchange 240-631
Gaithersburg - VERIZON MARYLAND, INC.

Exchange 240-632
Gaithersburg - VERIZON MARYLAND, INC.

Exchange 240-638
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-641
Chantilly - TIDALWAVE TELEPHONE INC.

Exchange 240-642
Chantilly - TIDALWAVE TELEPHONE INC.

Exchange 240-643
Beltsville - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-644
Washington - XO MARYLAND, LLC

Exchange 240-645
Washington - XO MARYLAND, LLC

Exchange 240-646
Washington - CAVALIER EAST LLC - MD

Exchange 240-652
Washington - XO MARYLAND, LLC

Exchange 240-654
-

Exchange 240-662
Silver Spring - VERIZON MARYLAND, INC.

Exchange 240-667
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-668
Lanham - STARPOWER COMMUNICATIONS, LLC - MD

Exchange 240-669
WASHINGTON - SBC TELECOM, INC. - MD

Exchange 240-671
WASHINGTON - SBC TELECOM, INC. - MD

Exchange 240-672
WASHINGTON - SBC TELECOM, INC. - MD

Exchange 240-674
Frederick - NEXTEL COMMUNICATIONS

Exchange 240-675
Frederick - DOBSON CELLULAR SYSTEMS, INC.

Exchange 240-676
Annapolis Junction - CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD

Exchange 240-678
Annapolis Junction - CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD

Exchange 240-681
WASHINGTON - ATX TELECOMMUNICATIONS SERVICES, LTD

Exchange 240-682
Lanham - STARPOWER COMMUNICATIONS, LLC - MD

Exchange 240-683
Gaithersburg - VERIZON MARYLAND, INC.

Exchange 240-684
COLLEGE PARK - VERIZON MARYLAND, INC.

Exchange 240-685
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-686
GERMANTOWN - VERIZON MARYLAND, INC.

Exchange 240-687
Annapolis Junction - CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD

Exchange 240-688
Adelphi -

Exchange 240-691
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-694
BETHESDA - VERIZON MARYLAND, INC.

Exchange 240-695
TEMPLE HILLS - VERIZON MARYLAND, INC.

Exchange 240-696
RESTON - LEVEL 3 COMMUNICATIONS, LLC - MD

Exchange 240-699
BUCKEYSTOWN - KMC TELECOM III, INC. - MD

Exchange 240-700
-

Exchange 240-703
-

Exchange 240-711
-

Exchange 240-715
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-718
Washington - XO MARYLAND, LLC

Exchange 240-720
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-722
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-723
Adelphi - MCI WORLDCOM COMMUNICATIONS, INC. - MD

Exchange 240-724
Washington - CAVALIER EAST LLC - MD

Exchange 240-725
LEXINGTON PARK - VERIZON MARYLAND, INC.

Exchange 240-727
Frederick - DOBSON CELLULAR SYSTEMS, INC.

Exchange 240-731
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-737
Washington - CAVALIER EAST LLC - MD

Exchange 240-743
-

Exchange 240-744
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-745
Washington - XO MARYLAND, LLC

Exchange 240-747
Washington - CAVALIER EAST LLC - MD

Exchange 240-750
- SOUTHWESTERN BELL MOBILE SYSTEMS, LLC - DC

Exchange 240-751
Chevy Chase - ADELPHIA BUSINESS SOLUTIONS OF MARYLAND, LLC

Exchange 240-752
Chevy Chase - ADELPHIA BUSINESS SOLUTIONS OF MARYLAND, LLC

Exchange 240-753
Chevy Chase - ADELPHIA BUSINESS SOLUTIONS OF MARYLAND, LLC

Exchange 240-755
-

Exchange 240-757
Reston - GLOBAL NAPS SOUTH, INC. - MD

Exchange 240-764
Washington - XO MARYLAND, LLC

Exchange 240-765
Washington - XO MARYLAND, LLC

Exchange 240-766
Washington - XO MARYLAND, LLC

Exchange 240-767
Washington - CAVALIER EAST LLC - MD

Exchange 240-770
- SBC TELECOM, INC. - MD

Exchange 240-773
Rockville - VERIZON MARYLAND, INC.

Exchange 240-776
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-777
Rockville - VERIZON MARYLAND, INC.

Exchange 240-778
Washington - XO MARYLAND, LLC

Exchange 240-779
Washington - CAVALIER EAST LLC - MD

Exchange 240-780
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-782
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-783
Baileys Crossroads - MTE, INC. DBA MTE PAGING NETWORK

Exchange 240-784
Frederick - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-786
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-787
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-788
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-790
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-793
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-794
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-804
Washington - XO MARYLAND, LLC

Exchange 240-811
-

Exchange 240-812
Washington - GLOBAL CROSSING LOCAL SERVICES, INC.-MD

Exchange 240-813
WASHINGTON - ATX TELECOMMUNICATIONS SERVICES, LTD

Exchange 240-818
SMITHSBURG - VERIZON MARYLAND, INC.

Exchange 240-821
- LIGHTWAVE COMMUNICATIONS, LLC - MD

Exchange 240-823
Washington - XO MARYLAND, LLC

Exchange 240-826
Rockville -

Exchange 240-832
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-833
Washington - XO MARYLAND, LLC

Exchange 240-835
Washington - ARBROS COMMUNICATIONS LICENSING COMPANY, N.E. - MD

Exchange 240-837
Washington - XO MARYLAND, LLC

Exchange 240-838
Beltsville - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-839
Adelphi -

Exchange 240-841
Baltimore - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-842
Baltimore - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-843
Baltimore - ALLEGIANCE TELECOM, INC. - MD

Exchange 240-844
Washington - XO MARYLAND, LLC

Exchange 240-845
Washington - XO MARYLAND, LLC

Exchange 240-846
Washington - XO MARYLAND, LLC

Exchange 240-848
WASHINGTON - SBC TELECOM, INC. - MD

Exchange 240-854
-

Exchange 240-855
Beltsville -

Exchange 240-857
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-863
Laurel - XSPEDIUS MANAGEMENT CO SWITCHES SERVICES, LLC - MD

Exchange 240-864
Washington - CAVALIER EAST LLC - MD

Exchange 240-865
Baltimore - SBC TELECOM, INC. - MD

Exchange 240-868
Washington - CAVALIER EAST LLC - MD

Exchange 240-876
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-880
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-882
Silver Spring - NEXTEL COMMUNICATIONS

Exchange 240-883
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-888
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-892
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-893
Washington - AT&T WIRELESS SERVICES, INC.

Exchange 240-895
LEXINGTON PARK - VERIZON MARYLAND, INC.

Exchange 240-897
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-898
WASHINGTON - FOCAL COMMUNICATIONS CORP OF THE MID-ATLANTIC

Exchange 240-899
Beltsville - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-900
-

Exchange 240-911
-

Exchange 240-912
Mc Lean - US LEC OF MARYLAND, INC.

Exchange 240-920
Frederick - LEVEL 3 COMMUNICATIONS, LLC - MD

Exchange 240-925
Adelphi - CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD

Exchange 240-929
Washington - CAVALIER EAST LLC - MD

Exchange 240-936
Washington - VERIZON MARYLAND, INC.

Exchange 240-938
Beltsville - OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC

Exchange 240-949
Washington - CAVALIER EAST LLC - MD

Exchange 240-950
-

Exchange 240-958
-

Exchange 240-959
-

Exchange 240-965
- PAETEC COMMUNICATIONS, INC. - DC

Exchange 240-976
Laurel -

Exchange 240-979
Frederick - LEVEL 3 COMMUNICATIONS, LLC - MD

Exchange 240-986
Washington - XO MARYLAND, LLC

Exchange 240-988
Beltsville - SPRINT SPECTRUM L.P.

Exchange 240-993
Washington - XO MARYLAND, LLC

Exchange 240-994
Annapolis Junction - CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD

Exchange 240-997
Annapolis Junction - CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD

Exchange 240-999
Washington - VERIZON MARYLAND, INC.