He was known as L.J. Klein when he finished as runner up to Miguel Proulx in Event #28: $2,500 Pot-Limit Omaha at the 2010 World Series of Poker. By the time he final tabled Event #50: $2,500 10-Game Mix (Six Handed) at the 2013 World Series of Poker, he was known as Loren Klein. His first bracelet came in the 919-player 2016 Event #45: $1,500 Mixed No-Limit Hold'em/Pot-Limit Omaha for $241,427. That year he also finished as runner-up to Brandon Shack-Harris in the 400-player Event #51 – $10,000 Eight-Handed Pot Limit Omaha World Championship. His second bracelet occurred in the 870-player 2017 Event #41: $1,500 Pot Limit Omaha for $231,483. His third bracelet came in the 476-player 2018 Event #49: $10,000 Pot-Limit Omaha 8-Handed Championship for $1,018,336 at a final table that included Shack-Harris (who finished third).