It was uncertain Wednesday night when the contract will end. The Guard announced on its website that it was pulling out after the current season, but Earnhardt's sponsor, Hendrick Motorsports, said the contract runs through the 2015 season.
"We have not been approached by the Guard about potential changes and plan to honor our current agreement," Hendrick Motorsports said in a statement.
The Guard has spent $32 million as an Earnhardt sponsor and $12 million on Rahal this year.
"We were informed this afternoon that the National Guard will end all sponsorship of motorsports, including both IndyCar and NASCAR at the conclusion of the 2014 seasons," Bobby Rahal, one of the owners of Rahal Letterman Lanigan Racing, said in a release. "This is obviously very disappointing news to Rahal Letterman Lanigan Racing given the significant incremental brand exposure we have worked to produce for the National Guard in our first season together, including various off-track marketing and advertising programs focused on supporting the mission set forth."
According to Maj. Gen. Judd H. Lyons, the Guard's acting director, the reasons for the departure were "significantly constrained resources and the likelihood of further reductions in the future call for more innovative and cost-effective ways of doing business."