Among the invitees are some who helped kill the Clinton administration's health care overhaul in the 1990s.
Everyone is supposed to be on his best behavior, but will that last? "This is a different day, " said Chip Kahn, a hospital lobbyist who opposed President Bill Clinton's plan and was to attend Thursday's gathering. "I think among most of the stakeholders, everyone wants to see this work. There is a tremendous feeling that it's time."
Now president of the Federation of American Hospitals, Kahn worked for the insurance industry in the Clinton years.
The difference this time, Obama argues, is that health care costs have become unsustainable, particularly in a sinking economy. The U.S. spends $2.4 trillion a year on health care, yet an estimated 48 million Americans lack coverage.
Obama's goal is health coverage for everyone.
Barnes said Obama is determined to pass health care legislation this year, and while he wants it to be bipartisan, he will not be deterred by obstruction from interest groups or ideological partisans.
"The president will make clear this has to be a bipartisan effort," Barnes said. "As for people who are there to set up hurdles, from his perspective that isn't tolerable. It's crucial to families, businesses and our nation's budget that we address the issue of exploding costs."
Senate Republican leader Mitch McConnell of Kentucky released a letter to Obama, saying his party is ready to work with the administration on health care, but warning that reforms should not lead to a government-run system, and must balance coverage expansions with curbs on costs.
Barnes said that Obama "walks into this conversation being pragmatic, being open. He knows that the American people are hurting" and are seeing their premiums rise.
But Barnes, interviewed Thursday on NBC's "Today" show, also said that "we have to be transparent about it. ... We will also hear the voices of the American people ... to make sure that health care reform gets before the president for his signature before the end of the year."
In support of Obama's efforts, liberal activists have mobilized to keep the pressure on Congress to pass legislation this year.
"It would be a mistake to dismiss this as a gabfest," Drew Altman, president of the Kaiser Family Foundation, said about Obama's meeting.
"It's an effort to keep the momentum going. The details are not going to be worked in two or three hours at a White House summit." There were concerns Wednesday about some of those details.
Senate Finance Committee Chairman Max Baucus, D-Mont., who will play a leading role in writing health care legislation, raised questions about the proposed $634 billion "down payment" for expanded coverage that Obama included in the 2010 budget he released last week.