The emails provided by the House Oversight Committee to The Wall Street Journal cover messages Mr. Gruber sent from January 2009 through March 2010. Committee staffers said they worked with MIT to obtain the 20,000 pages of emails.

They depict frequent consultations between Mr. Gruber and top Obama administration staffers and advisers in the White House and the Department of Health and Human Services on the Affordable Care Act. They show he informed HHS about interviews with reporters and discussions with lawmakers, and that he consulted with HHS about how to publicly describe his role…

The White House has described Mr. Gruber as having a limited role in crafting the law. President Barack Obama in 2014 said Mr. Gruber was “some adviser who never worked on our staff.” In testimony last year before Congress, Mr. Gruber disagreed with the widespread characterization of his role as the “architect” of Mr. Obama’s health-care plan.

“His proximity to HHS and the White House was a whole lot tighter than they admitted,” said Rep. Jason Chaffetz, (R. Utah), chairman of the House oversight committee. “There’s no doubt he was a much more integral part of this than they’ve said. He put up this facade he was an arm’s length away. It was a farce.”