Atlanta declined their half of Hand's $7 million mutual option for 2024 on Sunday.
Hand picked up the save in Tuesday's 7-6 victory over Philadelphia. He notched one strikeout in a perfect 10th inning.
The Rockies traded Hand to Atlanta on Tuesday in exchange for Alec Barger, Robert Murray of FanSided.com reports.
Hand (2-1) earned the win in Wednesday's 4-3 win over Pittsburgh, striking out two over 1.2 perfect innings.
Hand allowed one hit and struck out one in a scoreless inning Sunday against the Mariners.
The Rockies signed Hand to a one-year, $2 million contract Saturday, Ken Rosenthal of The Athletic reports.
Hand (elbow) was activated from the 15-day injured list Friday and is on the Phillies' roster for the NL Wild Card Series against the Cardinals, Alex Coffey of The Philadelphia Inquirer reports.
Hand (elbow) thew a 25-pitch bullpen session Monday and is scheduled to face live hitters Wednesday, Matt Gelb of The Athletic reports.
Hand was placed on the 15-day injured list S, retroactive to Sept. 22, with left elbow tendinitis.
Hand struck out one in a perfect inning and earned a save over the Pirates on Friday.