The 25-year-old will drive one of JR Motorsports' Chevrolets in the second-tier series from next year, in what will be just his second full season after part-time efforts in 2007 and 2009.
Bires has competed in 12 events this season, driving for five different teams with a fourth-place finish at Nashville being his best result thus far while driving for Kevin Harvick Inc. He also finished fifth at Iowa, driving for Braun Racing.
"I can't thank Dale Jr enough for this opportunity," Bires said. "JR Motorsports is a quality organisation. They win races and they contend for championships. As a driver, that's all you can ever ask for.
"They have a tremendous infrastructure of support with Rick Hendrick and Tony Eury Sr. These are people who know how to win races, know how to win championships and know what it takes to be successful."
The team has yet to confirm whether Bires will drive the #88 or the #5 car, a decision relying on sponsorhip. Brad Keselowski, who has driven the #88 since 2007, is set to leave the squad to join Penske Racing for full-time assaults in the Sprint Cup and Nationwide Series.
"Kelly is a talented young driver and we want to give him the opportunity to showcase that talent," said Earnhardt. "Our whole premise at JR Motorsports from the beginning has been to take up-and-coming drivers, give them the chance to drive good equipment and help them reach the next level.
"Kelly has a lot of promise. I noticed his potential earlier this year and we are glad to have him at JR Motorsports."
JR Motorsports has won three races in the Nationwide Series this season, all with Keselowski who currently lies third in the championship.
Xisco heads back to SpainKeselowski signs with Penske
