Although no specific timeline was given for the announcement of legislation, the CR passed by Congress last week gives the various committees until January 27th to present a bill.  Per Reuters:

"It's very much formulated down to the final strokes. We haven't put it in quite yet but we're going to be doing it soon," Trump told the Post, adding he was waiting for his nominee for health and human services secretary, Tom Price, to be confirmed.

The plan, he said, would include "lower numbers, much lower deductibles," without elaborating.

"We're going to have insurance for everybody," Trump said. "There was a philosophy in some circles that if you can't pay for it, you don't get it. That's not going to happen with us."

"It'll be another plan. But they'll be beautifully covered. I don't want single-payer. What I do want is to be able to take care of people," he added.