Obamacare is going to have unintended consequences that will need to be addressed, but imperfections will be changed over time, The Cleveland Clinic's CEO told CNBC on Thursday.
"It's an experiment that we've never done before. So unfortunately I don't think we say how this is going to turn out," Dr. Toby Cosgrove said on "Squawk Box."
"We know we need to take cost out of the [health] system. That's what's happening right now," said Cosgrove, who heads a $6 billion hospital and health system. He spoke a day after President Barack Obama defended the law in the face of tech problems with the federal online insurance exchange and outrage over the cancellation notices going out to people who bought health insurance on their own.
(Read more: Obamacare can't make health care cheaper: Langone)
Obama said "bad apple" insurers are to blame for those canceled plans, because their coverage doesn't meet the new standards of the law. He also stressed in his speech from Boston that people who find themselves in this situation will be able to find health coverage on the federal and state Obamacare exchanges.
"The law is going to continue to be refined for the next four or five years, just as Medicare was" after it was rolled-out in 1966, Cosgrove said. "This is probably as big a social change that's happened since the New Deal came along, because it affects 100 percent of the people in the United States and their health care and the cost of that," he said.
The fallout over the Obamacare rollout and the government shutdown earlier this month has knocked Obama's approval rating to the weakest of his presidency, according to a new NBC News/Wall Street Journal poll. Dropping by 5 percentage points in less than three weeks, just 42 percent of Americans approve of the president's job performance, while 51 disapprove.
(Read more: Obama's standing drops after health-care fiasco, shutdown)
Obamacare was also a major focus on Capitol Hill this week with Health and Human Services Secretary Kathleen Sebelius appearing before a House panel and apologizing to frustrated people trying to sign up for coverage. She said she's accountable for the government-run website failures since the Oct. 1 launch. Sebelius predicted the problems with the federal portal, serving 36 states not operating their own, will be fixed by Nov. 30.
"It's obviously disappointing that we're having so many problems getting this organized. But it has not had major effect," Cosgrove said. "If they can get these problems cleared up by the end of the year, hopefully we'll go forward with the program."
—By CNBC's Matthew J. Belvedere. Follow him on Twitter @Matt_SquawkCNBC.