"Regardless of your income, age, geography, or race, everyone is gaining access to coverage or better coverage under the Affordable Care Act," said HHS Secretary Sylvia Burwell.
The report noted that one of the few groups that had a "notably smaller decline in uninsured rates was Americans living in poverty in states that chose not to expand Medicaid," the joint federal-state health coverage program that covers primarily poor people. Nineteen states have not expanded Medicaid eligibility to include nearly all poor adults, as was authorized and largely federally funded by the ACA.
In Medicaid expansion states, the overall uninsured rate of residents declined by almost 50 percent. But in non-expansion states, the uninsured rates dropped by less than 32 percent.
HHS, citing an Urban Institute estimate, said that if the non-expansion states adopted expansion, an additional 4.1 million people would gain health coverage.
The ACA led to reductions in the uninsured rates through several avenues. First, the law allowed adults below the age of 26 to remain on their parents' health plans. The law then, beginning in 2014, mandated that nearly all Americans have some form of health insurance or be subject to a tax penalty.
Obamacare also authorized the creation of government-run marketplaces, or exchanges, to sell private health plans, with people with low or moderate incomes eligible for subsidies to reduce their monthly premium payments, and in many cases to reduce their out-of-pocket health costs. The law also mandated that employers with 50 or more full-time workers offer them health coverage or face a fine. And it allowed states to expand Medicaid.
According to recent surveys, the national uninsured rate has fallen to 9.1 percent this year. Before passage of the ACA, the uninsured rate was just under 16 percent.