Two tickets, one in Missouri, one in Pennsylvania, matched the numbers drawn in the Powerball lottery, splitting the estimated $261.3 million jackpot, lottery officials said.
No information about the winners or where the tickets were sold was available early Thursday.
The numbers in Wednesday night's drawing were 19-21-26-31-51 and the Powerball was 40.
The jackpot has surpassed $200 million four times since Powerball began in 1992. The largest jackpot was the Christmas 2002 prize of $314.9 million, won by a West Virginia contractor.
Sales for this drawing had flagged over the long July Fourth weekend but picked up starting Monday.
"As people started going back to work this week, getting back into their normal routine, then across the Powerball states we saw sales going up," said Mary Neubauer, Iowa Lottery spokeswoman.
The latest winners can select half of a $147 million lump sum or opt for annual payments of more than $4.2 million over 30 years. Both figures are before taxes, Neubauer said.
Powerball, the nation's largest lottery game, is sold in 24 states, the District of Columbia and the U.S. Virgin Islands.
At a downtown Des Moines store, business analyst Kim Mingles grabbed 30 tickets for her office pool hours before the drawing.
The co-workers "decided we were buying new houses and paying bills," if they won, said Mingles, 40, of Bevington, Iowa.