A winner who opts to take the lump-sum payment will receive an estimated $516.8 million pre-tax; the annuity, which divides the pot into 30 years of annual payments, is worth $1 billion. Those who choose the annuity will immediately receive a payment, which will increase by 5% each year for the next 29 years. USA Mega, which analyzes lottery jackpots, reports the average annuity payment will be $33.3 million pre-tax.

Off the top, the federal government withholds 24%. That means if you take the lump sum payment, $124 million will go to the IRS immediately. But Emily Irwin, managing director of advice and planning at Wells Fargo’s Wealth and Investment Management, says to remember the winner will undoubtedly wind up in the top marginal tax bracket, 37%, next year, and will owe the difference then. (That’s 37% on income above $578,125.)

“Some portion will need to be set aside to pay next spring,” Irwin tells Fortune. After federal taxes have been taken, USA Mega estimates the lump sum will be worth $325 million while the annuity will be worth an average of $21 million per year.

State taxes on lottery winnings differ

That’s where things get a little more complicated, and of course, every financial situation is different. Someone who gives away a large chunk of their winnings to charity will be taxed much differently than someone who doesn’t, for example. But here’s an estimate of how much a single winner would owe in taxes on the $1 billion jackpot.

Fourteen states don’t levy additional tax on lottery winnings: Alabama, Alaska, California, Delaware, Florida, Hawaii, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Utah, Washington, and Wyoming. If you bought a ticket in one of these states, you’ll come out with more winnings than individuals who bought tickets in other states.

Winners in those could pay as much as 10.75% in state or local taxes, according to USA Mega. It notes there may be “niche tax law” that could cause the actual rates to differ from the below, and that state lotteries typically withhold things like delinquent child support payments and back taxes from winnings when applicable.

• Washington, D.C.: 10.75%
• Maryland: 8.95%
• New York: 8.82%
• New Jersey: 8%
• Oregon: 8%
• Wisconsin: 7.65%
• Minnesota: 7.25%
• Connecticut: 6.99%
• Montana: 6.75%
• South Carolina: 6.50%
• West Virginia: 6.50%
• Vermont: 6%
• Rhode Island: 5.99%
• New Mexico: 5.90%
• Idaho: 5.80%
• Georgia: 5.75%
• Iowa: 5%
• Kansas: 5%
• Maine: 5%
• Massachusetts: 5%
• Mississippi: 5%
• Nebraska: 5%
• Illinois: 4.95%
• Louisiana: 4.75%
• North Carolina: 4.75%
• Oklahoma: 4.75%
• Arkansas: 4.70%
• Kentucky: 4.5%
• Michigan: 4.25%
• Colorado: 4%
• Missouri: 4%
• Virginia: 4%
• Ohio: 3.99%
• Indiana: 3.15%
• Pennsylvania: 3.07%
• North Dakota: 2.90%
• Arizona: 2.50%

Your local jurisdiction may also levy taxes on the winnings, depending on where you live (New York City and Yonkers, for example, do).

If you win, Irwin advises finding a tax attorney and financial planner before accepting the prize. They can help you make moves to limit your tax burden or simply accept it anonymously and plan how to use it for the future.

And if you’re entering a pool with your coworkers, friends, or family members to increase your odds of winning, Irwin advises making sure all tickets are shared and that you have a digital payment trail to prove you participated.

Top Powerball and Mega Millions jackpots

There have been two previous Powerball jackpots that topped $1 billion. In 2016, a $1.586 billion pot was split between three winners, and last year there was a single winner for a massive $2.04 billion prize.

In combination with the Mega Millions lottery, there have been seven jackpots worth at least $1 billion, including four since the beginning of 2022. Earlier this year, a single winner was chosen for the $1.35 billion Mega Millions pot. There was also a $1.54 Mega Millions jackpot in 2018, claimed by one winner; a $1.337 Mega Millions prize in July 2022 won by one person; and a $1.05 billion Mega Millions pot split between a group in Jan. 2021.

There is also a massive Mega Millions drawing on Tuesday, with the jackpot reaching $640 million. The $1 billion Powerball drawing is on Wed., July 19.