Uninsured rate for wealthy Americans tanked under the ACA, but the exact amount is hard to pin down

Health insurance forms
More research shows the individual mandate helped drop uninsured rates by double-digits, but finding the exact percentage is difficult. (Getty/vinnstock)

The uninsured rate dropped heavily for high-income Americans under the Affordable Care Act, but pinning down the exact percentage is difficult, according to a new analysis.

Determining the impact of individual policies within the law is arduous as well.  

An analysis by Matthew Fiedler of the USC-Brookings Schaeffer Initiative for Health Policy found the uninsured rate for people with family incomes above 400% of the poverty line declined 20%-40% with the implementation of major ACA provisions, depending on the data source and age group.

According to the report, research by the federal Current Population Survey found that the uninsured rate for high-income group fell from 6.4% in 2013 to 4.87% in 2016, a 24% drop, while the American Community Survey said it fell from 5.5% to 3.41% over the same period, a 39.4% decrease. 

RELATED: More research forecasts a stormy 2019 for ACA premiums

Additionally, research from the Commonwealth Fund has found that young, high-income men have done particularly well under the 2010 law. The foundation reported the uninsured rate among men 26-34 with incomes above 400% of the poverty line fell from 11.7% in 2013 to 7.2% in 2015.

Both studies appear to show that the changes to insurance regulations under the Affordable Care Act have actually driven young, healthy people to the marketplace instead of away from it.

But that could change with the repeal of the individual mandate next year.

RELATED: More young, high-income men have coverage under the ACA despite predictions they would flee the market

Fiedler added that decreased uninsured rates despite increasing premiums costs under the ACA imply that the individual mandate is likely responsible for the drop in the uninsured rate. Republicans have claimed repealing the mandate is unlikely to drop coverage rates. 

There is "strong evidence that the change in the uninsured rate for this income group was caused entirely or almost entirely by the ACA rather than other economic and demographic changes," Fiedler said. "This conclusion is consistent with prior research for the population as a whole, which found that the ACA drove the decline in the overall uninsured rate since 2013."

The analysis, however, cautioned that determining the impact of the mandate on insurance coverage is difficult due to the implementation of other ACA coverage provisions at the same time.