Area code 240 serves parts of Maryland, including Cumberland, Frederick, Hagerstown, and Gaithersburg. It was created in 1997 as an overlay to area code 301.
- 240-209
- Landline Number
- Indian Head, MD
- 240-214
- Landline Number
- Mechanicsville, MD
- 240-215
- Landline Number
- Frederick, MD
- 240-220
- Landline Number
- Poolesville, MD
- 240-225
- Landline Number
- Frederick, MD
- 240-230
- Landline Number
- Hughesville, MD
- 240-231
- Landline Number
- Hagerstown, MD
- 240-236
- Landline Number
- Frederick, MD
- 240-239
- Landline Number
- Leonardtown, MD
- 240-243
- Landline Number
- Gaithersburg, MD
- 240-246
- Landline Number
- Gaithersburg, MD
- 240-249
- Landline Number
- Mechanicsville, MD
- 240-250
- Landline Number
- Brandywine, MD
- 240-252
- Landline Number
- Gaithersburg, MD
- 240-254
- Landline Number
- Hughesville, MD
- 240-255
- Landline Number
- Poolesville, MD
- 240-256
- Landline Number
- Leonardtown, MD
- 240-264
- Landline Number
- Beltsville, MD
- 240-275
- Landline Number
- Grantsville, MD
- 240-282
- Landline Number
- Mechanicsville, MD
- 240-284
- Landline Number
- Frostburg, MD
- 240-285
- Landline Number
- Frederick, MD
- 240-306
- Landline Number
- Gaithersburg, MD
- 240-307
- Landline Number
- Emmitsburg, MD
- 240-313
- Landline Number
- Hagerstown, MD
- 240-315
- Landline Number
- Frederick, MD
- 240-323
- Landline Number
- Emmitsburg, MD
- 240-324
- Landline Number
- Clarksville, MD
- 240-327
- Landline Number
- Gaithersburg, MD
- 240-329
- Landline Number
- Hagerstown, MD
- 240-341
- Landline Number
- Adamstown, MD
- 240-342
- Landline Number
- Sandy Spring, MD
- 240-345
- Landline Number
- Sandy Spring, MD
- 240-347
- Landline Number
- Hagerstown, MD
- 240-356
- Landline Number
- Frederick, MD
- 240-359
- Landline Number
- Indian Head, MD
- 240-360
- Landline Number
- Silver Spring, MD
- 240-361
- Landline Number
- Gaithersburg, MD
- 240-362
- Landline Number
- Cumberland, MD
- 240-364
- Landline Number
- Gaithersburg, MD
- 240-366
- Landline Number
- Williamsport, MD
- 240-369
- Landline Number
- Mount Airy, MD
- 240-376
- Landline Number
- Hughesville, MD
- 240-377
- Landline Number
- Indian Head, MD
- 240-378
- Landline Number
- Cumberland, MD
- 240-379
- Landline Number
- Frederick, MD
- 240-382
- Landline Number
- Hagerstown, MD
- 240-385
- Landline Number
- Myersville, MD
- 240-389
- Landline Number
- Sandy Spring, MD
- 240-390
- Landline Number
- Sandy Spring, MD
- 240-404
- Landline Number
- Gaithersburg, MD
- 240-405
- Landline Number
- Frederick, MD
- 240-415
- Landline Number
- Frederick, MD
- 240-420
- Landline Number
- Hagerstown, MD
- 240-434
- Landline Number
- Leonardtown, MD
- 240-436
- Landline Number
- Ijamsville, MD
- 240-437
- Landline Number
- Sandy Spring, MD
- 240-452
- Landline Number
- Hagerstown, MD
- 240-466
- Cell Number
- Mechanicsville, MD
- 240-477
- Landline Number
- Gaithersburg, MD
- 240-489
- Landline Number
- Poolesville, MD
- 240-500
- Landline Number
- Hagerstown, MD
- 240-526
- Landline Number
- Leonardtown, MD
- 240-527
- Landline Number
- Hagerstown, MD
- 240-528
- Landline Number
- Hughesville, MD
- 240-529
- Landline Number
- Frederick, MD
- 240-530
- Landline Number
- Silver Spring, MD
- 240-536
- Landline Number
- Sandy Spring, MD
- 240-538
- Landline Number
- Leonardtown, MD
- 240-559
- Landline Number
- Sandy Spring, MD
- 240-566
- Landline Number
- Frederick, MD
- 240-575
- Landline Number
- Frederick, MD
- 240-583
- Landline Number
- Beltsville, MD
- 240-586
- Landline Number
- Frederick, MD
- 240-597
- Landline Number
- Gaithersburg, MD
- 240-629
- Landline Number
- Frederick, MD
- 240-631
- Landline Number
- Gaithersburg, MD
- 240-632
- Landline Number
- Gaithersburg, MD
- 240-652
- Landline Number
- Mechanicsville, MD
- 240-683
- Landline Number
- Gaithersburg, MD
- 240-685
- Landline Number
- Brandywine, MD
- 240-686
- Landline Number
- Gaithersburg, MD
- 240-699
- Landline Number
- Adamstown, MD
- 240-720
- Landline Number
- Gaithersburg, MD
- 240-722
- Landline Number
- Sandy Spring, MD
- 240-734
- Landline Number
- Hagerstown, MD
- 240-751
- Landline Number
- Gaithersburg, MD
- 240-779
- Landline Number
- Sandy Spring, MD
- 240-780
- Landline Number
- Gaithersburg, MD
- 240-787
- Landline Number
- Brandywine, MD
- 240-801
- Landline Number
- Silver Spring, MD
- 240-812
- Landline Number
- Poolesville, MD
- 240-813
- Landline Number
- Gaithersburg, MD
- 240-818
- Landline Number
- Smithsburg, MD
- 240-823
- Landline Number
- Brandywine, MD
- 240-837
- Landline Number
- Hughesville, MD
- 240-883
- Landline Number
- Sandy Spring, MD
- 240-901
- Landline Number
- Silver Spring, MD
- 240-903
- Landline Number
- Silver Spring, MD
- 240-912
- Landline Number
- Gaithersburg, MD
- 240-920
- Landline Number
- Cumberland, MD
- 240-964
- Landline Number
- Cumberland, MD
- 240-979
- Landline Number
- Cumberland, MD
- 240-993
- Landline Number
- Indian Head, MD