Maryland Lottery spokeswoman Carole Everett did not identify the winner, who will share the largest lottery prize in history.
Everett said the winner will remain anonymous, but lottery officials plan to share a "story line" with the public during a news conference Tuesday morning.
A Westport woman drew international attention last week when she said she had bought one of the three winning tickets sold nationwide in the $656 million drawing on March 30.
Mirlande Wilson, a mother of seven who emigrated from Haiti, could not immediately be reached for comment Monday evening. Her cellphone voice mail was full.
The winning ticket was sold at a 7-Eleven on Liberty Road in Milford Mill about four hours before the drawing.
The New York Post reported last week that Wilson was fighting over the ticket with her co-workers at a nearbyMcDonald'srestaurant.
The co-workers said Wilson bought the ticket as part of a workplace pool and should share the winnings. Wilson acknowledged purchasing tickets for the pool but said she bought the winner with her own money.
As the week went on, she told reporters that she wasn't sure the ticket was a winner, that she had hidden it at the restaurant and that she had lost the ticket.
Everett said last week that she had heard rumors about Wilson and other supposed winners, but "we're not going to chase gossip."
"That one just happened to make the newspaper," she said. "We do not expect this woman to come in."
At a news conference Wednesday, Wilson wouldn't so much as nod to acknowledge that she had the ticket. Her attorney, Edward Smith Jr., said he could not "say with any certainty that this ticket exists."
Smith also said that Wilson "doesn't want 15 minutes of fame. … She wants, I think, a lifetime of being anonymous."
Lottery officials held a news conference of their own Thursday to stress that no one had claimed the prize and to urge lottery players to recheck their numbers before throwing out their tickets.
Reached after that event, Wilson said she was not "ready" to cash in her ticket and that she was "a little bit stressed."
The holder of a ticket purchased in Kansas came forward last week and will also remain anonymous, officials there said. No one has turned in the winning ticket purchased in Illinois.
Each successful claimant stands to take home more than $100 million after taxes.