MCI, Inc. was a telecommunications company. For a time, it was the second-largest long-distance telephone company in the United States, after AT&T. WorldCom grew largely by acquiring other telecommunications companies, including MCI Communications in 1998, and filed for bankruptcy in 2002 after an accounting scandal, in which several executives, including CEO Bernard Ebbers, were convicted of a scheme to inflate the company's assets. In January 2006, the company, by then renamed MCI, was acquired by Verizon Communications and was later integrated into Verizon Business.

Bernard John Ebbers was a Canadian businessman and the co-founder and CEO of WorldCom. Under his management, WorldCom grew rapidly but collapsed in 2002 amid revelations of accounting irregularities, making it at the time one of the largest accounting scandals in the United States. Ebbers blamed his subordinates but was convicted of fraud and conspiracy. In December 2019, Ebbers was released from Federal Medical Center, Fort Worth, due to declining health, having served 13 years of his 25-year sentence, and he died just over a month later.