List of United States telephone companies

Regional Bell Operating Companies

• AT&T Inc.: Alabama, Arkansas, California, Florida, Georgia, Illinois, Indiana, Kansas, Kentucky, Louisiana, Michigan, Mississippi, Missouri, Nevada, North Carolina, Ohio, Oklahoma, South Carolina, Tennessee, Texas, Wisconsin
• Verizon: Delaware, District of Columbia, Maryland, Massachusetts, New Jersey, New York, Pennsylvania, Rhode Island, Virginia
• CenturyLink: Arizona, Colorado, Idaho, Iowa, Minnesota, Missouri, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Texas, Utah, Washington, Wyoming
• Frontier Communications: Alabama, Arizona, California, Connecticut, Florida, Georgia, Illinois, Indiana, Iowa, Michigan, Minnesota, Mississippi, Nebraska, Nevada, New Mexico, New York, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Texas, Utah, West Virginia, Wisconsin,

Other major incumbent local exchange carriers

• CenturyLink, in addition to its role as the RBOC in the areas gained from its acquisition of Qwest, CenturyLink serves mainly rural and smaller city local exchanges in 33 states.
• Frontier Communications, in addition to its role as the RBOC for West Virginia, now serves mainly rural and some suburban and smaller city areas in 27 other states. It also purchased AT&T's landline business in Connecticut in 2013, though these are not considered an RBOC, as the Southern New England Telephone Company, from which they descend, was a franchisee of the Bell System, and not subject to the same regulations after the Bell System breakup.
• Windstream, founded in 2006 with the spinoff of Alltel's wireline division and simultaneous merger with Valor Telecom, serves mainly rural areas in 29 states.
• Consolidated Communications, in addition to access lines in Maine, New Hampshire, and Vermont, in Northern New England which it gained from its acquisition of FairPoint, also serves rural areas in 21 other states.
• Telephone and Data Systems, serves mainly rural areas in parts of 36 states.
• Cincinnati Bell, which serves the greater Cincinnati area, and Hawaii due to its acquisition of Hawaiian Telcom was not included in the Bell System breakup of 1984 because the former AT&T held only a minority stake in that company.
• Verizon, in addition to its role as a RBOC in its areas retained in the East, serves former GTE areas in Pennsylvania and Virginia. Verizon formerly served California, Florida and Texas before selling to Frontier Communications in 2016.
• Claro Puerto Rico, which serves every exchange in Puerto Rico, has been owned by the international telecommunications giant América Móvil since in 2007.

Regional telephone companies and VOIP providers by state