Evidence that Obamacare is working

The Affordable Care Act, love it or hate it, is doing one thing right: It's reducing the ranks of Americans going without health insurance.

The health care law is credited with helping to lower the share of Americans without health insurance to 10.4 percent last year, a decline of almost three percentage points from 2013, according to new data released by the U.S. Census Bureau. That drop is the largest recorded since 2008, the bureau said.

About two-thirds of Americans have private health insurance, with most of those receiving coverage through employer-based programs. The biggest improvements in coverage rates were among those who directly purchased their own policies, for which many of those consumers turned to Obamacare exchanges, as well as Medicaid enrollment, which was expanded in many states under the law.

Last year, 33 million Americans lacked health insurance for the entire calendar year, compared with 41.8 million in the prior year, Census said. That means about 8.8 million Americans gained health insurance coverage in 2014.

While other surveys and polls have recorded improvements in the uninsured rate since the ACA's rollout, the Census data is considered the benchmark for such measures.

Still, a significant variation in coverage remains between U.S. states, with generally higher uninsured rates in states that declined to expand Medicaid coverage. Texas, Florida and Mississippi, which are among that group, have uninsured rates of more than 14 percent, among the highest in the country, Census said. The state with the lowest rate of uninsured residents is Massachusetts, at 3.9 percent.

Still, 33 million Americans lack health insurance, and more than half of those households earn less than $50,000 a year. About 9 million Americans without health insurance are living under the poverty line, Census said. While that's still high, it's a decline from the 10.9 million poor Americans who lacked insurance in 2013.

It's not higher wages that are helping Americans afford health insurance, however. Incomes remain stubbornly stagnant, according to Census data also released on Wednesday. Americans are actually earning less than they were in 2013, and median household income remains far below its peak in 1999.

Obamacare, which went into full effect last year, offers subsidies for middle- and low-income Americans to help them afford health care coverage. That has made buying health insurance more feasible for many families, although some insurers are planning to boost rates in 2016. The real test may come in the next few years, especially if Americans face bigger premiums under the ACA.