Buffett is insuring the contest, which is free to enter and sponsored by Quicken Loans, the Los Angeles Times reported Tuesday.
Quicken Loans, based in Detroit, paid Buffett an undisclosed fee to cover the $1 billion prize in the event that someone turns in a perfect run through the NCAA men's college basketball tournament that begins March 18.
Billionaire wannabes interested in entering the contest must first sign up at quickenloansbracket.com. The contest is limited to the first 15 million people who register.
Yahoo! Sports is handling technology support for the contest and requires entrants to sign up for a free Yahoo! account to submit a bracket, the Times said.
A skilled handicapper would have about a 1-in-1-billion chance of completing a perfect bracket, Ezra Miller, a Duke University mathematics professor, told the newspaper.
The semi-final and final games will be in Arlington, Texas.