According to the United States Code, which has a special section for commemorative coins: “No coin issued under this subsection may bear the image of a living former or current President, or of any deceased former President during the 2-year period following the date of the death of that President.”
Archive article: https://archive.is/28sTn
“How soon can you get these out to the public?”
“With some luck, should be able to start circulation in two years”