The numbering plan area includes the cities of Schererville, Chesterton, Lake Station, Lowell, Crown Point, Cedar Lake, Hobart, Whiting, Gary, Hammond, East Chicago, Merrillville, Munster, Griffith, Highland, Portage, Valparaiso, Michigan City, Ogden Dunes, St. John, La Porte, DeMotte, Roselawn, Kouts, Lake Village, and Rensselaer.
The numbering plan area encompasses the cities of Schererville, Chesterton, Lake Station, Lowell, Crown Point, Cedar Lake, Hobart, Whiting, Gary, Hammond, East Chicago, Merrillville, Munster, Griffith, Highland, Portage, Valparaiso, Michigan City, Ogden Dunes, St. John, La Porte, DeMotte, Roselawn, Kouts, Lake Village, and Rensselaer.