Last year was the first year that more than 90 percent of Americans had health insurance, new federal data shows.

On Tuesday the Centers for Disease Control and Prevention released its annual look at health insurance coverage in the United States. It shows that coverage rates have gone up this decade, particularly after Obamacare's health insurance expansion took effect.

In 2015, 9.1 percent of people lacked health insurance — a 2.4 percentage point decrease from 2014. That works out to 7.4 million fewer people lacking coverage.

You can see that health coverage was on the rise in the early 2010s, before Obamacare's health insurance expansion kicked in. But the really big drop in the uninsured rate happened in 2014 and has continued into 2015, as millions of Americans have gained coverage through Medicaid and the Obamacare marketplaces.

Further reading:

Explaining single-payer health care