The German driver was previously with the outfit in 2016 and achieved tremendous success. By the end of the season, he had taken four wins and second place in the drivers' standings. He drove the Corvette C7 GT3-R prepared by RWT Racing last year and finished seventh overall with team-mate, Sven Barth.
Jahn will share a cockpit this season with Jannes Fittje, who is completely new to the ADAC GT Masters. "Of course, I'm looking forward to the season ahead, and above all, to being back with KÜS Team75 Bernhard," said Jahn. "It's going to be great! We were very successful together. I'm also really looking forward to driving the new Porsche 911 GT3 R. I've already been out in it once but will now be able to test it properly and really put the car through its paces. Working with my new team mate should be good too. I've not actually met him yet but am fairly sure that we'll get on well together."
Team Principal Timo Bernhard added: "Even though it's later than planned, we're delighted that we'll soon be lining up to contest the 2020 season of the ADAC GT Masters. Everyone in the outfit is well prepared and really looking forward to the first race weekend. Jannes Fittje and David Jahn in car number 18 should make a terrific pairing."
Porsche works driver Simona de Silvestro and ex-Porsche Junior Klaus Bachler will line up in the sister car, bearing start number 17. "So you see," said Bernhard in conclusion, "We've got excellent crews for both our cars!"