Reutimann, 41, who has been with the team since its debut season in the NASCAR Sprint Cup in 2007, will leave the squad after driving the #00 Toyota in the last three races of the year.
NASCAR veteran Martin has been linked to drive a partial season at MWR next year and the team is set to announce plans for 2012 on Friday at Texas Motor Speedway.
Martin is leaving Hendrick Motorsports at the end of the year as Kasey Kahne joins the team to take over the #5 car that the 52-year-old has raced for the past three years.
"David has been a significant part of Michael Waltrip Racing since the very beginning and will forever be a part of our heritage," said team co-owner Michael Waltrip.
"We want to thank David for his contribution to our growth and success over the past five years and wish him well in the future."
In 168 Cup career starts, all for MWR, Reutimann claimed the team's only victories thus far, winning at Charlotte in 2009 and last year at Chicagoland.
