The Mega Millions jackpot could be the second largest for a single winner after surging past $400 million this week.
As it stood on Wednesday, the potential cash payout sat at about $216.4 million, but that amount, along with the total jackpot, would grow as people buy more tickets before Friday's drawing at 8 p.m., said California Lottery spokesman Mike Bond.
The odds of winning were 1 in 259 million on Wednesday, Bond said, with tickets offered in 43 states, alongside Washington, D.C., and the U.S. Virgin Islands.
The Lucky family in Maryland won $189 million in October, the largest so far this year, according to Mega Millions' website.
Ticket holders in Kansas, Illinois and Maryland won the largest jackpot, $656 million, in March 2012.