On January 21, 2024, Costa Firenze bid farewell to its last voyage under the banner of Costa Cruises, concluding a two-week Mediterranean and Canary Islands cruise with a final stop in Savona. The next stop is Cadiz, Spain where the ship will undergo dry-dock at Navantia shipyard and will be rebranded as Carnival Firenze.

Costa Firenze will become the latest addition to Carnival Cruise Line's expanding fleet. Having served its time under the Costa Cruises flag, is making its way to the United States. The official launch is scheduled for April 25, 2024, at the port of Long Beach near Los Angeles.

Costa Firenze follows its sister ship, Costa Venezia, which underwent a similar transition and is now sailing as Carnival Venezia under the Costa by Carnival concept. This initiative involves transferring ships within the Carnival Corporation group to maximize operational efficiency.

Despite the rebranding, Costa Firenze's distinctive Italian design will be retained during its conversion to Carnival Firenze. Carnival Cruise Line is actively promoting the two sister ships as part of its "Carnival Fun Italian Style" experience. The ships, originally constructed for Costa, share a fundamental structure based on the Vista Class, which is familiar to Carnival Cruise Line guests who have experienced vessels like Carnival Vista, Carnival Horizon, and Carnival Panorama.