A new analysis suggests that 52 million Americans could be denied health insurance if the Affordable Care Act is repealed. 

The analysis done by the Kaiser Family Foundation relies on the fact that one in four non-elderly adults in the U.S. has a medical condition that could lead an insurer to deny them coverage if the ACA, which prohibits insurers from denying coverage based on pre-existing conditions. 

The report’s authors note many of the 52 million people are currently covered by an employer-based health plan or Medicaid. Therefore, the report is not predicting that that many people would be without coverage, but that roughly a quarter of the U.S. population would be unable to buy insurance in the individual market if necessary. 

The analysis does not account for the potential of a replacement plan that would maintain all or part of the ACA’s pre-existing condition provision. 

President-elect Donald Trump has said that he wants to maintain the current protection for those with medical conditions, while a replacement proposal floated by Republicans would protect people who maintain “continuing coverage” from being denied but would not guarantee that those without insurance can purchase it. 

The actuarial challenge that Republicans face in crafting a replacement is that maintaining protections for those with pre-existing conditions is made considerably harder — some believe impossible — without maintaining the requirement that individuals buy insurance. However, Republicans have insisted that the mandate has got to go. 

A spokeswoman for America’s Health Insurance Plans suggests to the Washington Post that allowing insurers to levy penalties or require waiting periods of those who do not maintain continuing coverage could be one way to encourage people to sign up. 

The Kaiser analysis also sheds light on the health disparities between states. In Colorado, which regularly scores high in a number of health metrics, such as tobacco use and obesity rates, only 22 percent of the population would be likely to be denied coverage, Kaiser estimates. In Mississippi and West Virginia, two of the country’s poorest states, 34 percent would risk rejection.