Pascal Wehrlein has described his graduation to the series as "a dream come true" following the announcement that he will replace the retiring Ralf Schumacher at Mercedes.
Formula 3 racer Wehrlein, 18, will become the youngest driver to start a DTM event when he makes his series debut at Hockenheim in May, having only raced a car for the first time in ADAC Formel Masters in 2010.
"It's especially nice that I will be making my DTM debut with RSC Mucke Motorsport, having driven for them in Formula ADAC and then the F3 Euro Series," he said.
"It's like a dream come true, and now I can't wait to get down to the business of setting up my new car for the season-opener."
Wehrlein was runner-up in last year's F3 Euro Series to Daniel Juncadella - the man who will be his RSC Mucke team-mate - as well as winning rookie of the year honours in the championship.
Mercedes motorsport chief Toto Wolff believes that his approach of selecting a DTM line-up that includes only one race winner in Gary Paffett, and has an average age of just 23, will pay dividends in the long run.
"Pascal Wehrlein is another promising young driver who perfectly fits our philosophy with regard to DTM drivers," Wolff said.
"We are consciously taking a different track with signing Pascal. He is one of five drivers who are all still very young, but we are confident that this new approach will benefit our brand.
"With an average age of 23 years, we may have the youngest team of drivers in the DTM, but so far, every one of them has proven skill in the world's leading junior series."
Wehrlein's signing for RSC Mucke means that both Robert Wickens and Roberto Merhi will be promoted to HWA cars alongside Paffett and Christian Vietoris.
It also means that there is now a spare seat at Mucke's F3 European Championship team alongside Felix Rosenqvist, Mitchell Gilbert and Roy Nissany.
Wehrlein, who had previously committed to an F3 campaign with the squad, drove during the official test at Barcelona last week.
DTM line-up: Manufacturer Team Drivers BMW Schnitzer Bruno Spengler/Dirk Werner RBM Augusto Farfus/Joey Hand RMG Martin Tomczyk/Andy Priaulx MTEK Timo Glock/Marco Wittmann Audi Abt M Ekstrom/J Green/T Scheider/A Tambay Rosberg Edoardo Mortara/Filipe Albuquerque Phoenix Mike Rockenfeller/Miguel Molina Mercedes HWA G Paffett/C Vietoris/R Merhi/R Wickens Mercedes RSC Mucke Pascal Wehrlein/Daniel Juncadella