Federal officials said today that during the first week of open enrollment for the health law’s online marketplaces, 462,125 people selected health plans, with just over half of those return customers.

The figures were the first weekly snapshot promised by the Department of Health and Human Services to provide details about exchange enrollment.  The figures are preliminary and cover enrollment from Nov. 15 through Nov. 21 in the federal exchange, used by residents of 37 states.

The remaining states and the District of Columbia run their own marketplaces and their information was not included. The figures may fluctuate from week to week based on a variety of factors, such as consumers changing or canceling plans, officials said.

HHS Secretary Sylvia Burwell called the numbers “a solid start” but added the agency has “a lot of work to do every day between now and Feb. 15” when  open enrollment ends.

The first week’s tally was a dramatic improvement over last year’s, when healthcare.gov‘s myriad computer problems caused the site to malfunction for millions of people. Some state exchanges also had problems, hindering enrollment efforts.

During a call with reporters, HHS officials said now the website would be able to withstand peak demand periods, such as those predicted for Dec. 15, when consumers must sign up and pay their first month’s premium if they want their coverage to begin Jan. 1, and for Feb. 15 when the 2015 enrollment period ends.

Today’s report noted that the average wait time for the federal exchange call center was just over three minutes and that more than one million consumers had submitted applications for coverage.

HHS officials also announced new partnerships aimed at boosting enrollment. Deals with Westfield Shopping Centers, the National Community Pharmacists Association and the XO Group, which owns popular websites such as The Knot, are part of the agency’s efforts to reach more consumers and provide them with information about the health law.

Kaiser Health News (KHN) is a national health policy news service. It is an editorially independent program of the Henry J. Kaiser Family Foundation.

For young people, turning 21 is generally a reason to celebrate reaching adulthood. If they’re insured through the federal health insurance marketplace that operates in about three dozen states, however, their birthday could mean a whopping 58 percent jump in their health insurance premium in 2015, according to an analysis by researchers at the Center on Budget and Policy Priorities.

The reason: They’re no longer considered children under the age-rating rules insurers use to set premiums.

Many 21-year-olds who qualify for premium subsidies will be able to sidestep the rate increase if they re-evaluate their coverage options on the federal marketplace before Feb. 15, when the annual open enrollment period ends. If they don’t, they’ll generally be automatically renewed into the same plan and with the same premium tax credit they had in 2014.

“If they don’t come back to the marketplace, they’re going to get a premium tax credit that’s based on their age rating as a child, and that premium difference is going to hit them,” says Judith Solomon, a vice president for health policy at the budget center.

Families with federal marketplace plans whose now 21-year-old children are covered as dependents will face a premium jump as well.

Under the health law, insurers can no longer base premiums on people’s health or pre-existing medical conditions. They’re permitted to apply just four premium rating factors in their calculations: age, where someone lives, how many people are going to be covered and whether someone uses tobacco. The law also prohibits premiums for older adults from being more than three times higher than those for younger adults.

Because of age rating, premiums for most adults will rise slightly every year as they get older. But with children, it’s different. Insurers apply the same age-rating factor to all children when computing their premiums. When children turn 21, however, the insurer begins to compute their premiums based on an adult age-rating factor, which results in that 58 percent premium increase.

Young people who go back to the marketplace to shop for a 2015 plan can generally avoid any age-related premium increases. They likely qualify for premium tax credits that are available to people with incomes between 100 and 400 percent of the federal poverty level ($11,670 to $46,680 for an individual). If they return to the marketplace, their premium tax credit will be adjusted to cover the higher age-related premium for their 2015 coverage.

“We’ve been encouraging everyone to update their profiles on healthcare.gov so they can ensure that they have a tax credit that reflects what they should be getting,” says Jen Mishory, executive director at Young Invincibles, an advocacy group for young people.

Please contact Kaiser Health News to send comments or ideas for future topics for the Insuring Your Health column.

Kaiser Health News (KHN) is a national health policy news service. It is an editorially independent program of the Henry J. Kaiser Family Foundation.

HHS announces partnerships to promote Health Insurance Marketplace starting on busiest shopping weekend of the year