Visconti, 33, moves from Movistar where he has spent the last five seasons. The three-time Italian national road champion has won stages in the Giro d’Italia and claimed the king of the mountains jersey in last year’s edition of the race.
Boaro, 29, joins from Tinkoff and will look to support Nibali in next season’s Grand Tours.
"At Bahrain Merida we are very pleased to welcome such talented cyclists as these two riders, we are sure they will contribute a very important part to the team and what we want to achieve, from our side we will go out of our way to make things as convenient as possible for them to be able to their dedicate work in the best possible way," Brent Copeland, the team’s general manager said in a press release.
The team did not disclose the length of either rider’s contracts.
The team are set to announce further signings in the coming days and weeks and have confirmed to Cyclingnews that they have submitted all the needed documentation to the UCI as part of the WorldTour license process.
If, as reported, the Bahrain Merida team takes over the Lampre Merida WorldTour license then all contracted riders at Lampre Merida for 2017 would transfer to the Bahrain Merida squad for the start of next season.
The futures of Rui Costa and Diego Ulissi, both out of contract at Lampre Merida, remain unclear with negotiations still on going.