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By David Morgan
WASHINGTON, March 11 (Reuters) - The Obama administration said on Tuesday that 4.2 million people have signed up for private health insurance under Obamacare, and indicated that total enrollment could surpass a 6 million-enrollee forecast by the end of March.
New enrollment data for a five-month period from Oct. 1 though March 1 came out as the administration threw its public relations campaign into overdrive, with President Barack Obama appearing for an interview on the comedy website, "Funny or Die," in a direct appeal to the site's audience of young adults.
Healthy enrollees aged 18 to 34 are vital to the success of new online health insurance marketplaces set up in all 50 states under the Patient Protection and Affordable Care Act. The administration is targeting younger Americans because they are cheaper to insure and can compensate for older, sicker policyholders who have been able to obtain affordable insurance due to the law.
Tuesday's data showed the level of young adult participation stuck at 25 percent of total enrollment for the second month in a row.
However, officials predicted that enrollment would skyrocket over the next 20 days, pushing totals significantly higher with a rush of younger enrollees.
"We do believe millions more Americans will come in and enroll in coverage before the March 31 deadline," said Julie Bataille, a spokeswoman for the Centers for Medicare and Medicaid Services, the government's lead Obamacare agency.
Bataille declined to issue a specific forecast. But her prediction suggests administration officials are confident that Obamacare enrollment will meet or exceed the nonpartisan Congressional Budget Office's (CBO) revised estimate of 6 million private insurance enrollees.
CBO initially forecast 7 million marketplace enrollees but scaled back that estimate after last year's botched rollout, in which the federal website HealthCare.gov was paralyzed by technical problems. Those problems continue to hobble enrollment efforts for state-run marketplaces in Hawaii, Massachusetts, Maryland and Oregon.
Enrollment advanced by 940,000 people in February, amid independent signs of a sustained decline in the United States' huge uninsured population of nearly 50 million people. A recent Gallup survey showed the percentage of Americans without health coverage at 15.9 percent in early 2014, down from an all-time high of 18 percent last summer, with declines in every major demographic group below age 65.
Eighty-three percent of Obamacare enrollees qualify for federal subsidies that help low-income people pay for health coverage, the data showed.
"What we're finding is that as more Americans learn just how affordable marketplace insurance can be, more are signing up to get covered," U.S. Health and Human Services Secretary Kathleen Sebelius told reporters in a teleconference.
But there were key gaps in the government data regarding who was signing up.
Officials did not have enough data to say how many enrollees were previously uninsured, versus those moving into Obamacare coverage from other plans, including policies canceled last year. A recent survey by the consulting firm McKinsey & Co found that 27 percent of February enrollees were previously uninsured.
The administration was also unable to say how many people who have signed up for coverage have actually enrolled by paying their first month's premium. The McKinsey study showed that more than three-quarters of February enrollees had made a premium payment.
Republicans zeroed in on the lack of detail to call on Obama to delay the law's tax penalty for those who fail to enroll in coverage by March 31.
"The administration won't tell us how many people have actually paid for a plan or how many were previously uninsured," said Brendan Buck, spokesman for House Speaker John Boehner. "But what we do know is that young adults - those who the White House repeatedly said are critical - are deciding the healthcare law is a bad deal."
Anticipating an enrollment surge, Officials said HealthCare.gov continues to operate smoothly with low error rates and fast page-loading speeds following last year's emergency effort to salvage the website.
But the problems faced by state-run exchanges that continue to be troubled were obvious in the latest enrollment data.
Connecticut, a leading Obamacare success story, has enrolled more than 57,000 people in private insurance since Oct. 1.
But two larger states, Massachusetts and Maryland, have signed up only about 13,000 and 38,000 respectively because of marketplace problems. Oregon has also enrolled only 38,000, while Hawaii, Obama's home state, has signed up just 4,661.
The watchdog Government Accountability Office is probing states with problem launches to determine how hundreds of millions of dollars on Obamacare grants were spent. (Reporting by David Morgan; Editing by Jonathan Oatis)
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