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Information about Area Code 240

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:

• Allegany
• Charles
• Frederick
• Howard
• Garrett
• Montgomery
• Prince George's
• Washington
• St. Mary's

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

• List of North American area codes
• North American Numbering Plan
• North American Numbering Plan Administration
• NANPA Area Code Map of Maryland
• Whitepages Area code Map

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.