Sources said Caldwell-Pope will re-sign on a one-year, $12 million deal and that Stephenson has agreed to a one-year, $4.5 million deal.
McGee and the Lakers reached agreement on a one-year deal worth the minimum, league sources told ESPN. McGee has played the past two years for the Golden State Warriors.
Caldwell-Pope, 25, will head into his second season with the Lakers after finishing a one-year, $18 million deal. He is a 3-D, catch-and-shoot player who figures to fit well alongside James.
Stephenson, 27, is known as a LeBron antagonist, and the two have had testy moments in the playoffs, but James has never had a personal issue with the defensive guard, sources said.
The 6-foot-5 guard became available after the Indiana Pacers declined his option for the 2018-19 season. Indiana wanted to go after bigger names in free agency and planned to discuss bringing Stephenson back.
Once James committed to the Lakers, Stephenson was a top player on the team's priority list.
The Lakers are heard to be offering only one-year deals to maximize their cap space for the summer of 2019.
The Associated Press contributed to this report.