Some 3 million Americans who lack health insurance could gain coverage, if only their states would accept the Medicaid funding that the Affordable Care Act provides. Two years into Obamacare, the arguments in favor of extending this coverage have only grown stronger.

Opponents have warned, for example, that giving health benefits to able-bodied adults will discourage them from working. But a comparison of states that have expanded Medicaid and those that haven’t — part of a collection of new Obamacare studies published Tuesday — found that expansion had no significant effect on employment levels among the newly eligible.

What Medicaid expansion has changed, however, is the number of uninsured who are treated in hospitals. In states that went along with the program — Washington state inclued — the share of uninsured patients in hospitals fell from 12 percent to 6 percent; other states saw no change. Fewer uninsured patients means hospitals have more money to spend on things like research, improved care and worker salaries.

Some conservative states have tried an alternative to the expansion: Rather than add qualified people to Medicaid rolls, they have used the federal money to enroll them in private insurance plans. And this strategy seems to improve access to medical care just as well, another study shows.

A handful of states — including Louisiana, South Dakota and Virginia — now appear closer to reversing their earlier opposition to expanding Medicaid. The new data show there are still economic, and humanitarian, reasons to go ahead.

The above editorial appears on Bloomberg View at www.bloomberg.com/view.