Medicaid recipients get the biggest dollar value in health care as a percentage of their income, while those with employer-sponsored health insurance get the smallest dollar value. (Photo: Shutterstock)

While higher-income Americans may pay the most in dollars toward the nation's health care system, what they fork over pales in comparison as a share of income to what the nation's poor have to cough up.

So says a new RAND Corporation study, which finds not only is the system regressive, but families in the highest-income group (out of five) pay 16 percent of their income toward health care while households in the bottom fifth pay an average of 33.9 percent of their income toward health care.

The middle three groups are on the hook for between 19.8 percent and 23.2 percent of their income. Health care spending itself accounted for nearly 18 percent of the U.S. gross domestic product in 2015, the year for which data was used from the Survey of Income and Program Participation, the Medical Expenditure Panel Survey, the Kaiser Family Foundation/Health Research Education Trust Employer Health Benefits Survey, the American Community Survey and the National Health Expenditure Accounts.