President Donald Trump’s acting chief of staff said the Trump administration plans to send a short summary of its health care “principles” to Congress as the basis for potential legislation to replace Obamacare, just as it did for Republicans’ tax-cut bill in 2017.

“We are doing the same thing on this that we did with taxes,” Mick Mulvaney said on CNN’s “State of the Union” on March 31. “We sent principles to the Hill, I think it was one or...