The employees of North American Stamping Group in Portland, Tennessee held the winning ticket that was drawn on Saturday after the prize money grew for two months, Tennessee Lottery officials said in a statement.
"The friends ... have been playing together for years and have a variety of plans for the winnings, including helping others," lottery officials said.
The jackpot soared from $403 million to $420.9 million on Saturday due to a spate of late ticket-buying.
The money is paid out over 30 years, with the option of a lump sum payment, which officials said would add up to about $254.7 million.
Powerball, one of several games run by the Multi-State Lottery Association, a non-profit owned and operated by member states' lotteries, is available in 44 states, the District of Columbia, Puerto Rico and the U.S. Virgin Islands.
The prize was among the top 10 largest in the history of the Powerball lottery. Powerball has yielded the largest-ever U.S. lottery prize, a $1.6 billion sum split between three winning tickets in January.