The Patient Protection and Affordable Care Act of 2010 (PPACA) may have been highly effective at getting U.S. residents who earn more than $90,000 per year to get health coverage.

Stephanie Marken, an analyst at Gallup, has published data supporting that conclusion in a comparison of results from telephone interviews with about 45,600 U.S. adults conducted from July 1 through Sept. 30 with results from similar interviews conducted in late 2013, before major PPACA coverage expansion and subsidy programs came to life.

The surveys were sponsored by Healthways, a health care management company.

Between the fourth quarter of 2013 and the third quarter of 2015, the likelihood that a survey participant would report being uninsured fell 32 percent. The overall uninsured rate dropped 5.5 percentage points, to 11.6 percent.

For people with annual incomes under $36,000, the likelihood of being uninsured decreased 28 percent, and the uninsured rate fell to 22.2 percent.

The likelihood of being uninsured fell just 21 percent for people with annual incomes from $36,000 to $89,999. In the latest quarter, those participants’ uninsured rate was 9.2 percent.

For people with $90,000 or more in annual income, the likelihood of being uninsured plunged 48 percent. Their uninsured rate sank to 3 percent.

PPACA provides cash that states can use to expand access to Medicaid and the Children’s Health Insurance Program (CHIP) for low-income residents. It also provides subsidies that moderately low-income consumers can use to buy and use private health coverage through the new PPACA health insurance exchange system.

PPACA provides no coverage purchase subsidies for people who earn more than 400 percent of the poverty level, but it has prohibited insurers from using personal health information in decisions about whether to issue coverage, and it does impose a tax penalty on many Americans who fail to have what federal regulators classify as an adequate level of coverage.

Some have wondered whether the tax penalty and changes in medical underwriting rules would be enough to persuade the remaining uninsured people with high incomes to get covered.

See also: PPACA subsidy gap hurts the moderately broke

The new figures suggest that the rules have succeeded at expanding high-income Americans’ insured rates, but that some middle-income consumers are still having trouble finding affordable coverage they want to buy.

In related news, Marken looked at the survey participants’ sources of health coverage.

Use of six of the seven types of coverage increased between late 2013 and the latest quarter. The likelihood of using individual or family coverage increased 20 percent, for example. About 21 percent of the people in the new survey sample said they had individual or family coverage.

The one type of coverage with a falling share was coverage from a “current or former employer.”

Forty-three percent of the people in the new sample said they had employer-sponsored health coverage, but the likelihood that an individual would have employment-based coverage was 2.7 percent lower than in late 2013.

See also: Uninsured rate falls again