President Donald Trump’s campaign promise to leave the Medicare program intact could hinder his administration’s efforts to reduce healthcare costs, experts said last week.

The Trump administration’s options to cut healthcare costs are “much more limited” without making changes to Medicare, Douglas Holtz-Eakin, former head of the Congressional Budget Office, said during a conference on Thursday. Gail Wilensky, former head of what was then called Health Care Financing Administration — now the Centers for Medicare & Medicaid Services — under President George H.W. Bush, concurred, according to Bloomberg BNA.

“Medicare definitely needs to come up on the table,” Wilensky said. “I am disappointed that President Trump has put that off.”

David Cutler, a Harvard University economics professor who worked on the Affordable Care Act, noted that Medicaid may end up being used as a “piggy bank” to provide funds for tax cuts for high-income people and cover subsidies for middle-income people to purchase health insurance. Wilensky agreed, adding she was “worried” about whether Medicaid will be used to fund other healthcare programs.

The experts also noted that legislation proposed to replace the Affordable Care Act will likely be similar in cost to the ACA, although an official budget estimate on the bill from the CBO has yet to be completed.