Service Employees International Union President Andy Stern formally called it quits on Wednesday, resigning his post in a much-anticipated announcement to the organization’s 2.2 million members.

Stern, a key ally of President Barack Obama, played a prominent role in shepherding organized labor’s support of the White House’s marquee legislative priority: health care reform.

“It is an incredible gift to have the chance to see one’s dreams realized,” Stern said Wednesday in a statement. “With the passage [of] healthcare reform and all that it means for people who work, I know that it is a moment for change and the right time for a renewal within SEIU.”

He will be replaced by SEIU Secretary-Treasurer Anna Burger.