In the wake of Congressional Republicans’ failure to drum up support for their health plan last month, the White House is negotiating to put repeal of the Affordable Care Act, or ACA, back on the table. While the previous proposal would have already driven up health care costs and stripped millions of coverage, the new proposal is rumored to include provisions that would undo protections for the more than 130 million Americans who have a pre-existing health condition.

Republicans are now discussing a provision that is effectively a sick tax on premiums: People with health conditions would be charged multiples more based on their medical history, paying above-standard rates for coverage. Even if the new plan preserved the ACA’s rules on guaranteed issue—meaning that issuers cannot deny coverage—consumers with pre-existing conditions could still be priced out of the market.

Prior to the ACA, insurers could discriminate against consumers based on their current health conditions and medical history. Consumers with common ailments, including asthma and high blood pressure, were charged higher rates. People with histories of serious conditions, such as cancer or heart attacks, were regularly denied coverage altogether.

About half of nonelderly Americans have one or more pre-existing health conditions, according to a recent brief by the U.S. Department of Health and Human Services, or HHS, that examined the prevalence of conditions that would have resulted in higher rates, condition exclusions, or coverage denials before the ACA. Approximately 130 million nonelderly people have pre-existing conditions nationwide, and, as shown in the table available below, there is an average of more than 300,000 per congressional district. Nationally, the most common pre-existing conditions were high blood pressure (44 million people), behavioral health disorders (45 million people), high cholesterol (44 million people), asthma and chronic lung disease (34 million people), and osteoarthritis and other joint disorders (34 million people).

While people with Medicaid or employer-based plans would remain covered regardless of medical history, the repeal of pre-ex protections means that the millions with pre-existing conditions would face higher rates if they ever needed individual market coverage. The return of pre-ex discrimination would hurt older Americans the most. As noted earlier, while about 51 percent of the nonelderly population had at least one pre-existing condition in 2014, according to the HHS brief, the rate was 75 percent of those ages 45 to 54 and 84 percent among those ages 55 to 64. But even millions of younger people, including 1 in 4 children, would be affected by eliminating this protection.

Jettisoning pre-existing condition protections would undermine the fundamental purpose of health insurance, including providing both the healthy and sick access to care and protecting families from financial ruin. Medical history should not be a barrier to affordable coverage.

Emily Gee is a Health Economist at the Center for American Progress.

To download the table by congressional district, click here.

Methodology

To calculate the number of people with pre-existing conditions by congressional district, we obtained estimates of the nonelderly population from the 2015 American Community Survey, or ACS, then subtracted out the number of nonelderly people who are covered by Medicare and would not be subject to possible discrimination based on a pre-existing condition. For the three states that recently redistricted—Florida, North Carolina, and Virginia—we used ACS county estimates and a crosswalk provided by the Kaiser Family Foundation to approximate current district boundaries for the 115th Congress.

We then applied pre-existing condition rates in the HHS brief to the ACS data to obtain the number of people in each age group with a pre-existing condition that could subject them to coverage carve-outs, higher rates, or coverage denials. Because HHS’s data source was 2014 Medical Panel Expenditure Survey and our population estimates are from the more recent 2015 ACS, our national total number of people with pre-existing conditions is slightly higher than that of HHS.