The pre-season tournament, which will take place across the US in the form of two groups of four teams, begins on July 26 and ends with the final at Miami's Sun Life Stadium on August 4.
Real won last year's competition, beating Chelsea in the final, while Milan finished in third place.
Both the Spanish and Italian giants will return to America this year, and will be joined by Premier League clubs United, Liverpool and Manchester City, as well as Inter, Roma and Olympiacos.
Liverpool's chief commercial officer Billy Hogan said the club were thrilled to be heading back to the country after enjoying a successful pre-season trip there in 2012.
"We were last in the USA in 2012 and thoroughly enjoyed our visit," he told the club's official website.
"So we are delighted to be invited to take part in the International Champions Cup and revisit again this year.
"This will be the club's seventh visit to North America, where we know we have a huge fan base, and being part of this tournament will allow us to bring the club closer to those supporters and engage with them once again."
