Government-sponsored health coverage increased for the fifth consecutive year, jumping from 31.2 percent to 32.2 percent. About a million more people were covered by federal health care programs including Medicare, Medicaid, Children's Health Insurance Program and military health care, the report shows.

But for the majority of Americans—those between 26 and 64 years old—the uninsured rate remained essentially unchanged. 

About 64 percent of Americans had private health insurance in 2011, unchanged from 2010, the Census report revealed. It was the first year in a decade the proportion of people with private insurance didn't fall.

But National Center for Policy Analysis senior fellow Devon Herrick says the “crisis of the uninsured” is far from over.

 “At least 30 million people will remain uninsured in once the Affordable Care Act is fully implemented,” he says, adding that it's largely because the penalties for forgoing health coverage are less than the cost of coverage. 

Moreover, he says, “maybe up to one-third of businesses will find it to their advantage to drop the employee health plan once their workers have access to subsidized coverage in the state health insurance exchanges. Another unintended consequence of the ACA is that many people will quite rationally wait until they become sick to enroll in health coverage due to new federal regulations that require insurers to accept all applicants regardless of health status.”