Nearly 6 million Americans so far have enrolled in insurance for 2016 through, President Obama announced on Friday, touting a big increase over last year that he said shows the Affordable Care Act is succeeding.

The number who have already signed up on the federal insurance exchange compares with 3.4 million at the same stage a year ago and comes at a significant moment in the ACA’s enrollment cycle: the deadline for people who want health plans in place starting on New Year’s Day. The figures also show that 2.4 million of the current total are new customers, about a third more than at this point last year.

This good news for proponents of the health-care law prompted the Obama administration to catapult it from what are normally routine announcements by federal health officials to the opening of a presidential press conference.

“The more who sign up, the stronger the system becomes,” Obama said at his final press conference of the year.

[ACA enrollment deadline extended two days after last-minute surge]

Earlier in the week, federal health officials signaled that interest in was running high. They granted a 48-hour extension to the original Dec. 15 deadline for obtaining insurance for Jan. 1, saying that the volume was so great that about 1 million people had been placed in waiting lines  to reach federal call centers or use the enrollment website.

(AP Photo/Andrew Harnik)

That surge occurred even though the administration recently tamped down public expectations for how many additional consumers are likely to get ACA insurance for the coming year.

This fall, Health and Human Services Secretary Sylvia Mathews Burwell issued a forecast that 10 million people will be covered through such health plans by the end of 2016 — only slightly more than expected for the end of this month. Burwell also has said that enrollment marketing efforts this year would focus on a cadre of 10.5 uninsured people who are eligible to sign up on the exchanges, intended for those without access to affordable insurance through an employer. HHS has forecast that one-quarter to one-third of them would enroll, which means that the 2.4 million new customers to date are already approaching that prediction.

The common wisdom has been that attracting new customers to would be more difficult in this third year, because people still uninsured have ignored or rejected two previous opportunities to gain coverage. On the other hand, the health-care law requires most U.S. residents to carry health insurance, and penalties next year will rise to $695 per person or 2 percent of income.

The figures announced by the president, and additional detail provided by federal health officials, reflect activity in 38 states that are now relying on They exclude the dozen states, plus the District of Columbia, that operate separate insurance marketplaces under the ACA.

In one important respect, the figures obscure the overall number of existing customers who will continue their coverage for another year. Under the rules for, the computer system re-enrolls people automatically if they do not sign up by mid-December. HHS officials have been cautioning consumers not to wait for this automatic enrollment, saying they could face spikes in insurance rates unless they shop around for the best available health plan.

The automatic renewals will take place by the end of this month, and federal health officials, briefing reporters on Friday, said that a majority had already enrolled but declined to specify how many had not done so.

Still, administration officials emphasized that use of, particularly in the days leading up to the deadline for Jan. 1 coverage, was running high.

“There was an unprecedented amount of traffic at the call center and an incredible amount of activity on,” said Andy Slavitt, acting administrator of the federal Centers for Medicare and Medicaid Services.

On Tuesday, 600,000 people chose health plans, the busiest day for since it first opened in October 2013, Slavitt said. The proportion of new customers increased as the deadline approached — so that newcomers accounted for nearly half of the 1.8 million people who enrolled during the last five days.

Robert Laszewski, a health-care consultant critical of the Affordable Care Act, contended that the higher enrollment so far reflects “significant churning,” as existing customers shop around on to try to avoid price increases in the plans they have now.

The enrollment season continues until Jan. 31. So it remains unclear whether the overall enrollment will be higher than expected by then, or whether a larger share are simply signing up for insurance earlier.