What is expected to be the largest Mega Millions jackpot ever is up for grabs tonight. The jackpot stands at an estimated $1.55 billion. If a winner takes the cash option, they would walk away with $757 million before taxes. Lottery officials say they won’t know if the jackpot hits record territory until closer to tonight’s drawing which happens at 11:00 p.m. If you do win, officials say the first thing you should do is sign the back of the ticket. The Mega Millions jackpot has been growing since mid-April.