According to a survey by the Commonwealth Fund, just 12.4% of Americans ages 19 to 64 are uninsured, a rate the Commonwealth Fund notes is statistically unchanged since 2016 despite efforts by the Trump administration to weaken the law.

But the number of underinsured Americans has steadily climbed, increasing from approximately 29 million in 2010 to 44 million in 2018. Underinsured is defined by those whose out-of-pocket costs or deductible comprise 5-10% of their income. These individuals find it more difficult to cover their medical bills, which can often turn into debt.

And both individuals who are insured through their employers or on their own are affected. The survey found that the number of underinsured Americans insured by their employers jumped from 17% in 2010 to 28% last year, while it has increased from 37% to 42% in the individual insurance market.

While changes by the Trump administration and Congress have not had a measurable effect on the uninsured rates, they have contributed to the rate of those who are underinsured. In particular, the Commonwealth Fund points to the erosion of cost protection and changes to employer plans, leading to growing health care costs overall.