The Pirates acquired Falter from the Phillies on Tuesday in exchange for Rodolfo Castro, Alex Coffey of The Philadelphia Inquirer reports.
The left-hander received some run in Philadelphia's rotation during the first six weeks of the season, but he was demoted to Triple-A in mid-May after he posted a 5.13 ERA, 1.44 WHIP and 28:8 K:BB in 40.1 innings. Falter was a solid swingman in 2022 with a 3.86 ERA across 20 appearances, and he could get a look in Pittsburgh's rotation down the stretch since Rich Hill was dealt to San Diego.