Which brings us to sort-of: From that point on, the champion has "visitation rights" to his Green Jacket. The jacket is considered his, and when he visits Augusta National at any point thereafter, he can retrieve and wear his jacket.
The official website of The Masters, Masters.com, explains a little further:
"Near the conclusion of the Masters, several Jackets are selected which could fit the possible winner during the presentation ceremony. The winner will have his measurements taken at the Club's Golf Shop or may provide measurements so that a custom made Green Jacket can be tailored. Typically, a multiple winner will have only one Green Jacket unless his size drastically changes."