The ACA has shielded some from rising costs, but for lower-income Americans who have employer-sponsored, private insurance plans, premiums and out-of-pocket costs have continued to rise. (Photo: Shutterstock)

Having a job—and the employer-sponsored health insurance that usually goes with it—is not a guarantee that an individual or family won't face financial hardship due to medical costs, according to a new analysis. The study finds that the percentage of income spent on health care by poorer Americans is more than three times the percentage spent by the wealthiest Americans.

The proposition that lower-income workers are more vulnerable to health care costs may not be surprising news, but the brief from the Peterson-Kaiser Health System Tracker provides real numbers in measuring the cost challenges that lower-income Americans face, even within the system of private, employer-based health insurance.

Related: 4 reasons employer-sponsored health insurance won't go away