Early evidence suggests that the advance premium tax credit likely contributed to an expansion of health insurance coverage in 2014 because it significantly reduced the cost of exchange plans' premiums for those eligible, according to a report released today by the Government Accountability Office. “Although there are limitations to measuring the effects of the APTC using currently available data, surveys GAO identified estimated that the uninsured rate declined significantly among households with incomes eligible for the APTC. For example, one survey found that the rate of uninsured among individuals with household incomes that make them financially eligible for the APTC fell 5.2 percentage points between September 2013 and September 2014. This expansion in health insurance coverage is likely partially a result of the APTC having reduced the cost of health insurance premiums for those eligible.” Most nonelderly adults had access to affordable plans, as defined by the Affordable Care Act, but some may face challenges maintaining coverage, GAO found. The ACA required that GAO review the affordability of health insurance coverage five years after enactment. In general, plans are considered affordable if their cost does not exceed 8% of household income (9.5% for employer-sponsored insurance).