By Amy Goldstein

The Washington Post

WASHINGTON — For the first time since the federal and state health insurance marketplaces opened in the early fall, the number of people who signed up for coverage in January exceeded the government’s expectations for the month, bringing the overall total to about 3.3 million.

Across the country, nearly 1.2 million people enrolled in health plans last month through the new insurance exchanges — more than federal officials had envisioned when they compiled monthly targets late last summer, weeks before the sign-ups began.

The figure is part of a detailed report issued Wednesday by the Obama administration, providing the latest look at how the effort to extend health insurance to more Americans is faring.

The report suggests that January was the first month in which enrollment was not dampened by serious computer defects, which initially stymied people trying to use the federal online marketplace,, and some of 14 similar marketplaces run by states.

Still, the lingering imprint of those early problems remains visible in the new report. Overall, the 3.3 million people who have signed up for coverage are about 1 million fewer than federal officials had anticipated by the end of January. That difference dovetails with a revised prediction last week by congressional budget analysts — that 6 million Americans, instead of 7 million, are likely to get insurance through the marketplaces by the time this year’s sign-up period ends March 31.

Winnowing the ranks of the uninsured is a central goal of the 2010 Affordable Care Act, which created the online marketplaces. In issuing the latest report, the government’s top health official and several aides said they did not yet have data to answer two critical questions: Of the people who have signed up, how many have paid their first premium so that they actually have coverage? And how many of them previously lacked insurance, as opposed to those who were switching insurance plans?

Nonetheless, Health and Human Services Secretary Kathleen Sebelius called the numbers “very, very encouraging news. . . .We are seeing a healthy growth in enrollment.”

Sebelius and the report focused attention on a slight increase in the proportion of young adults signing up for coverage — a part of the population whose participation is widely considered essential to keeping the marketplaces working well, because they tend to be healthy and, thus, inexpensive to insure. Of the people who selected a health plan last month, 27 percent were between the ages of 18 to 34 — the group considered young adults — compared with 24 percent for the previous three months combined. Both figures are substantially less than 40 percent, the level that research has suggested is desirable to help health plans sold through the exchanges keep their prices stable.

Although January was the first month that enrollment exceeded federal predictions, the number of people who signed up was lower than in December.