Shifting the U.S. health-care system from private and employer insurance toward a government-run program would likely lower administrative costs but could increase wait times and reduce access to care, the nonpartisan Congressional Budget Office said in a report that raised cautions for Democratic lawmakers who back an idea known as Medicare for All.

The report, released Wednesday, said more federal spending would be needed under legislation creating a government-run, Medicare for All system to largely replace private and employer insurance coverage with a single government program for everyone. The analysis doesn’t estimate how much funding would be required, however.

The report serves as a yardstick laying out possible pitfalls and advantages of instituting such a Medicare for All system, as well as the policy questions lawmakers would have to address.

By consolidating administrative tasks, the report says, their costs would likely fall under the new health system. But the design of the system would determine whether it lowers overall health-care spending.

A Medicare for All system would create incentives, such as access to expanded preventive care and other benefits that may improve people’s health, the report said. But it also said that extending coverage to more Americans could produce longer wait times and reduced access to care if there weren’t enough health workers.