The nation’s hospital industry warned President-elect Donald Trump and congressional leaders on Tuesday that repealing the Affordable Care Act could cost hospitals $165 billion by the middle of the next decade and trigger “an unprecedented public health crisis.”

The two main trade groups for U.S. hospitals dispatched a letter to the incoming president and Capitol Hill’s top four leaders, saying that the government should help hospitals avoid massive financial losses if the law is rescinded in a way that causes a surge of uninsured patients.

The letter, along with a consultant’s study estimating the financial impact of undoing the Affordable Care Act, makes hospitals the first sector of the health-care industry to speak out publicly to try to protect itself from a sharp reversal in health policy that Trump is promising and congressional Republicans have long favored.