After a summer of contentious public town hall debates and accusations, the president said that "The time for bickering is over. The time for games has passed. Now is the season for action [...] Now is the time to deliver on health care."
Mr. Obama spoke in favor of one of the most contentious points in the debate -- a public insurance plan that would provide competition to private insurers and an option for those who don't have insurance now. He compared it to the system of public universities that provides competition to private colleges.
But the public option has proved a dividing wedge, with Republicans and some more conservative Democrats saying they would not support a bill that includes it. So the president stopped short of insisting on a public option, as many more liberal Democrats had hoped he would.
"To my progressive friends, I would remind you that for decades, the driving idea behind reform has been to end insurance company abuses and make coverage affordable for those without it," he said. "The public option is only a means to that end, and we should remain open to other ideas that accomplish our ultimate goal."
Listen to analysts Mark Shields and David Brooks initial reactions to the speech:
The president laid out the broad outlines of a reform plan he said drew from the best ideas of Republicans and Democrats.
The reforms would include new insurance industry regulations that would prohibit insurance companies from denying coverage because of pre-existing conditions, and from the practice of rescission, or revoking customers' coverage when they become sick. It would also outlaw caps on the amount of coverage patients can receive in a year or lifetime.
The plan would also create an insurance exchange, a new marketplace in which individuals and small businesses could shop for insurance plans.
"As one big group, these customers will have greater leverage to bargain with the insurance companies for better prices and quality coverage," President Obama said.
The plan would include an individual mandate requiring all individuals to carry health insurance, and would provide tax credits and subsidies to help them afford it, Mr. Obama said. It would also require businesses above a certain size to either provide health care for workers or pay a fee to help cover the cost -- although the president said 95 percent of small businesses would be exempt from the requirement.
He also made a gesture to Republicans and others who have called for malpractice reform to be part of any health insurance reform plan, saying that he would go forward with some test programs on the issue.
"While there remain some significant details to be ironed out, I believe a broad consensus exists for the aspects of the plan I just outlined," President Obama said.
He also said that the plan's $900 billion cost over 10 years would be paid for mainly by eliminating waste and abuse in the current health care system, a claim that many analysts have questioned.
The president was speaking to two audiences in his address -- the lawmakers in the room with him, and the American public watching on television.
In the face of falling poll numbers that suggest that much of the public disapproves of his health care reform plans, one of Mr. Obama's main goals was to convince the public of the crucial need for reform.
"Our collective failure to meet this challenge -- year after year, decade after decade -- has led us to a breaking point," he said. "We are the only advanced democracy on Earth -- the only wealthy nation -- that allows such hardships for millions of its people."
On the NewsHour Wednesday, analysts Mark Shields and David Brooks both thought that the president largely conveyed his message successfully.
"I thought ... it was one of his best speeches as president," said Brooks. "I thought the weakest part is the cost part. There's really still nothing in here that will control costs."
After the speech, Rep. Charles Boustany of Louisiana, a heart surgeon, delivered the official Republican response.
"I read the bill Democrats passed through committee in July. It creates 53 new government bureaucracies, adds hundreds of billions to our national debt, and raises taxes on job-creators by $600 billion," he said. "The president had a chance tonight to take government-run health care off the table. Unfortunately, he didn't do it."
Watch more reaction from Shields and Brooks on the Obama speech and the GOP view:
The president was also addressing members of Congress, who returned to work this week after a tumultuous August recess. Neither chamber of Congress has formally brought any health care legislation to the floor yet, missing deadlines leaders had set earlier this summer.
Four of five Congressional committees have passed health reform bills, but none with any support from Republicans. The Senate Finance Committee, chaired by Democrat Max Baucus of Montana, is still negotiating a bill with a bipartisan group of six Senators. But Baucus this week said he would move legislation forward in the committee in two weeks whether the negotiators could reach a bipartisan agreement or not.
The president addressed his Republican opponents directly, saying that his door was open to anyone who came with serious proposals, but that he would not "waste time with those who have made the calculation that it's better politics to kill this plan than to improve it."
Analyst Mark Shields said he thought the president's speech energized the Democrats in the room.
"I think it made a difference in the hall," he said.
But Republican leaders remained skeptical, and mostly silent as Democrats applauded during the speech. In an unusual outburst, one, Rep. Joe Wilson, R-S.C., shouted "You lie!" when the president said that his reforms would not cover illegal immigrants.
House Minority Leader John Boehner told the Wall Street Journal that Republicans' opposition to the president's plan would remain firm, even without a public option. "Let's understand, it's not the only bitter pill in the plan," he said, referring to the tax increases and fees included to pay for it.
On Larry King Live, Sen. John McCain, R-Ariz., said "There's many things that we can agree on and work together. Republicans want reform." But he added "We're very concerned about the cost, [and] about the public option."
Editor's Note: This story was updated at 11:03 p.m. ET.
---- Compiled by the Online NewsHour