Reed has Type 1 diabetes and his sponsorship will be supported by Eli Lilly. He'll join Charlie Kimball of the IndyCar Series as two drivers competing in a national series with diabetes.
Reed will drive the No. 16 Ford full-time for Roush and compete for rookie of the year.
Reed has run three races this season for Roush, with a best finish of ninth at Richmond.
RFR has already announced a full-time Nationwide schedule for Trevor Bayne for 2014, and is still working on deals for Travis Pastrana and Chris Buescher.