Heavy ticket sales have boosted the top prize to $242 million, up from the first estimate of $237 million.
The jackpot has been without a winner for 14 consecutive biweekly drawings, dating back to early November. The chances of winning the jackpot are 1 in 175 million.
Mega Millions is played in 41 states and the District of Columbia.
On the Web: www.megamillions.com