Mercedes said the 37-year-old German had relinquished his seat in the DTM (German touring car) series for a new role as managing shareholder at RSC Mucke Motorsport where he will support young drivers.
Ralf is Germany's third most successful Formula One driver, with six race wins, behind brother Michael and triple world champion Sebastian Vettel.
"I've been thinking a great deal about my future during the last few weeks and have reached the conclusion that I am better able to support the extensive changes at Mercedes-Benz with regard to the DTM in a management role than at the wheel," he said in a statement.
"I am very grateful for more than two decades in professional motor racing and the last five years with Mercedes-Benz in the DTM.
"This represents an exciting challenge for me, helping the best young drivers with my know-how and expertise," added Schumacher.
Michael Schumacher, now 44, retired from Formula One last year after three comeback seasons with Mercedes. He won 91 races with Benetton and Ferrari.
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