Jeff Zients will serve as President Joe Biden’s next chief of staff, according to media reports on Sunday.

Zients, who helped steer the Biden administration’s Covid-19 response and carry out its ambitious vaccine campaign, briefly left the White House in April before returning in the fall to help the current chief of staff, Ron Klain, prepare for turnover in the administration following the midterm elections.

Klain has been open about his intent to eventually leave his post, and he is reportedly preparing to step down in the coming weeks, according to a Saturday report from The New York Times.

Klain, a longtime adviser to President Joe Biden, supported Biden through his 2020 campaign and has helped guide the Biden administration since he was elected to office. After the midterm elections in November and an action-packed two years in the White House, Klain has told colleagues that he is ready for something different, a Washington Post report said.

Klain previously acted as Biden’s chief of staff during former President Barack Obama’s first term, and he’s worked with Biden since he ran for president back in 1987. Zients, in contrast, has spent most of his career in the private sector and first made his foray into politics during the Obama administration.

Though Zients has a relatively limited political background compared to Klain, he is a “master implementer” and “engenders deep loyalty” from his colleagues, the Post reported.

A White House representative did not immediately respond to CNBC requests for comment.