Self-covered individuals are hit hardest, but employers providing coverage have fought back against rising costs by reducing plan benefits.

Deductibles are up 67% since 2010. That's seven times more than wages. And the cost of prescription drugs is out of sight.

Please consider Burden of Health-Care Costs Moves to the Middle Class

Overall, health-care spending across the economy reached 18.2% of gross domestic product as of June, up from 13.3% in 2000, according to Altarum Institute, a health research group.

David Cutler, a Harvard health-care economist, said this may be "a story of three Americas." One group, the rich, can afford health care easily. The poor can access public assistance. But for lower middle- to middle-income Americans, "the income struggles and the health-care struggles together are a really potent issue," he said.