Signing the world's number one ranked rider and his 3,233 ranking points all but ensures BORA-hansgrohe's step up to the WorldTour in 2017, a decision not officially announced by the UCI until the end of the year.
The Slovakian brings with him from Tinkoff his brother Juraj, Maciej Bodnar, Michael Kolar and Erik Baška.
“It is a great honour to welcome one of the most popular cyclists of our time in our team. That’s why we tried to provide familiar surroundings as far as possible. I think Peter’s trust in us proves that we did a good job the last years and have solid reputation in the peloton," team manager Ralph Denk said.
"I am very happy and sure that this partnership will be a successful one," he said.
The addition of Sagan means the first goal for BORA-hansgrohe in 2017 is the Classics.
“My goal is a well-balanced roster for the 2017 season. With Peter the Classics will be a big highlight for us. But we also want to play a role in the Grand Tours, therefore we still look for new signings," he said.
Current boss Oleg Tinkov seemingly gazumped an announcement of Sagan's move during the Tour de France.
Rumours have linked current naming rights sponsor, bicycle manufacturer Argon 18 with Astana for next year. The bicycle supplier for BORA-hansgrohe is therefore at this stage unclear.
BORA and hansgrohe are major brands in Germany - BORA manufactures cooking systems and hansgrohe, bathroom products.