The Obama administration's announcement that it will phase out its contracts with private prison companies has sent the stocks of two publicly traded prison companies plummeting. Both get about half their revenue from the federal government. A third prison company, Management and Training Corp., is a private company.

Here's a look at the companies:

Corrections Corp. of America

The company was founded in 1983, went public in 1986 and was listed on the NYSE in 1994. It reorganized into a real estate investment trust in 2013 and has prisons in 20 U.S. states and the District of Columbia, according to its website.

Headquarters: Nashville, Tennessee.

Employees: 14,055

Annual revenue: $1.79 billion in 2015, $1.65 billion in 2014

Number of prisons: Owns 74, manages 11 government-owned facilities.

GEO Group Inc.

Founded in 1984, it has technically operated as a real estate investment trust since 2013, with operations in the U.S., United Kingdom, Australia and South Africa. The company went public in 1994 and was listed on the NYSE in 1996.

Headquarters: Boca Raton, Florida.

Employees: 20,500

Annual revenue: $1.84 billion in 2015, $1.69 billion in 2014

Number of prisons: The company says it operates 104 "correctional, detention and residential treatment facilities" with 87,000 beds.

Management and Training Corp.

Founded in 1981, starting out in the federal Job Corps program. Its Education & Training division still has contracts with Job Corps centers in 16 states.

Headquarters: Centerville, Utah

Employees: 8,923

Number of prisons: It runs 26 state and federal prisons in Arizona, California, Florida, Idaho, Ohio, New Mexico, Mississippi and Texas.