Officials in South Carolina said they had a winner in their state. Not all states have reported results yet.
The $1.6 billion jackpot would be the largest prize in U.S. history and comes with a cash option of $913 million.
The winning numbers are: 5-28-62-65-70 Mega Ball: 5
If there had been no winner, the Texas lottery office announced, the jackpot would have climbed to $2 billion.