The picks are a conditional third-round selection in 2022 and a conditional fourth-rounder in 2023. The details of the conditions were not provided by either team in their statements announcing the trade.
Carter's contract carries an average annual value of $5.272 million through the end of the 2021-22 season. The Kings will retain 50 per cent of his remaining salary.
The 36-year-old has spent the last 10 years with the Kings, winning the Stanley Cup in 2012 and 2014. Carter has 390 goals and 751 career points in 1,080 NHL games with the Kings, Blue Jackets and Flyers. This season, he has eight goals and 19 points in 40 games.
The Penguins were expected to add a centreman given the injuries to pivots Evgeni Malkin and Teddy Blueger, the latter of which is nearing a return. In Carter, the club adds a versatile forward that can slot in as the team's 3C when their injured regulars return, or on the wing higher up in the lineup if need be.
Carter has a long history with new Penguins GM Ron Hextall, the latter having been the Flyers' director of player personnel when Philadelphia drafted Carter, and assistant GM with the Kings during Carter's two championship runs. The veteran centreman also has history with Sidney Crosby, having won an Olympic gold alongside the Penguins captain in 2014.