A new analysis suggests that 52 million Americans could bedenied health insurance if the Affordable Care Act is repealed.

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

The report’s authors note many of the 52 million people arecurrently covered by an employer-based health plan or Medicaid. Therefore, the report is notpredicting that that many people would be without coverage, butthat roughly a quarter of the U.S. population would be unable tobuy insurance in the individual market if necessary.

The analysis does not account for the potential of a replacementplan that would maintain all or part of the ACA’s pre-existingcondition provision.

President-elect Donald Trump has said that he wants to maintainthe current protection for those with medical conditions, while areplacement proposal floated by Republicans would protect peoplewho maintain “continuing coverage” from being denied but would notguarantee that those without insurance can purchase it.

The actuarial challenge that Republicans face in crafting areplacement is that maintaining protections for those withpre-existing conditions is made considerably harder — some believeimpossible — without maintaining the requirement that individualsbuy insurance. However, Republicans have insisted that the mandatehas got to go.

A spokeswoman for America’s Health Insurance Plans suggests tothe Washington Post that allowing insurers to levypenalties or require waiting periods of those who do not maintaincontinuing coverage could be one way to encourage people to signup.

The Kaiser analysis also sheds light on the health disparitiesbetween states. In Colorado, which regularly scores high in anumber of health metrics, such as tobacco use and obesity rates,only 22 percent of the population would be likely to be deniedcoverage, Kaiser estimates. In Mississippi and West Virginia, twoof the country’s poorest states, 34 percent would riskrejection.