Washington (CNN)If the United States Supreme Court decides to overturn a key provision of Obamacare allowing federal tax subsidies for health insurance, the administration doesn't have any backup plans to allow people to obtain coverage.
Sylvia Mathews Burwell, the Health and Human Services secretary, told lawmakers in a letter on Tuesday that millions of Americans would lose their health insurance if the court rules against President Barack Obama's administration in the case, which is expected to be decided by June.
A surprise rise in Obamacare enrollment 01:19
"[We] know of no administrative actions that could, and therefore we have no plans that would, undo the massive damage to our health care system that would be caused by an adverse decision," Burwell wrote.
The case, King v. Burwell, involves the tax credits meant to subsidize health insurance under President Barack Obama's landmark health law. The Affordable Care Act says people who sign up for health insurance through state-run exchanges are eligible for federal credits, but doesn't state specifically that people who enroll on the federal exchanges also qualify.
The tax subsidies are essential to Obamacare's success; the vast majority of people who have enrolled receive some type of credit.
"Millions of people would lose their health insurance subsidies and therefore would no longer be able to afford health insurance," should the court rule against the administration, Burwell wrote.
The Kaiser Family Foundation estimates 13.4 million Americans could lose their subsidizes if the court rules in favor of King v. Burwell's plaintiffs.
Republicans took the health secretary's letter as another indication of the law's problems.
"By admitting they have no contingency plan to assist the millions that may lose subsidies, the administration confirms how the misguided law is unworkable for the American people," Sen. Orrin Hatch, the Republican chairman of the Senate Finance Committee, said in a written statement.
The Supreme Court will hear oral arguments in the case next week.
