WASHINGTON (AP) —
    Midway through sign-up season, more young adults are getting coverage through President Barack Obama's health care law. The number of new customers is also trending higher, officials said Tuesday in an upbeat report.
    Outside analysts who reviewed the administration's update said it reflects encouraging progress, but that may not dispel questions about the long-term future of the health insurance markets created under Obama's 2010 overhaul. Premiums have been going up and getting new sign-ups remains a challenge.
    Administration statistics also showed some continuing problems verifying the citizenship and income of applicants for subsidized coverage. Consumer advocates say those issues generally stem from the complexity of the law, and that many people who run into verification problems simply drop out. Some become uninsured again.
    Health and Human Services Secretary Sylvia M. Burwell said more than 8.2 million people signed up or renewed coverage for 2016 from Nov. 1 through Dec. 19. Open enrollment ends on Jan. 31. People who remain uninsured after that risk rising fines.
    "We're off to a strong start," Burwell said Tuesday, noting that the numbers reflect only the 38 states using the HealthCare.gov website and call center. Major states running their own programs, including California and New York, were not counted in Tuesday's report, and their totals will be factored in later.
    About 2.4 million people who've signed up are new to HealthCare.gov, said Burwell, ahead of last year's levels.
    And 2.1 million are under age 35, a coveted demographic because young adults tend to be healthy and their participation helps keep premiums in check. The number of younger adults signed up is close to double what it was at this point last year.
    Obama's health care law offers subsidized private health insurance to people who don't have access to job-based coverage. This year nearly 85 percent of customers nationwide are receiving assistance that averages $271 a month.
    Between the insurance markets and the law's Medicaid expansion for low-income people, the health care law has helped bring down the nation's uninsured rate to 9 percent, a historic low. That translates to more than 16 million people gaining coverage since the law passed five years ago.
    Tuesday's update amounted to a half-time report on the 2016 enrollment season.
    Independent analysts said the administration should be able to meet or exceed its ultimate goal, which is having 10 million people signed up and paying premiums at the end of 2016. As of Sept. 30, the insurance markets had about 9.3 million people enrolled and paying their premiums.
    In the past, about 1 in 5 of those signed up at the start of the year has dropped out later. Some probably found jobs with health insurance benefits.
    Elizabeth Carpenter of the consulting firm Avalere Health said the administration seems to be on track to exceed its 2016 enrollment goal, after attrition.
    "The bigger question is if this sort of modest year-over-year growth is sufficient to ensure a balanced, stable risk pool over time and continue to attract insurer participation," added Carpenter.