Raikkonen's name was on the official entry list released Monday in the No. 87 under the ownership of NEMCO Motorsports run by Nemechek, who formed an alliance with Busch to make the deal work.
Raikkonen made his NASCAR debut in Friday night's Truck Series race for Kyle Busch Motorsports, finishing 15th. He hinted then about the possibility of running in the Nationwide race and Busch acknowledged that a car was in his shop even though he doesn't have a Nationwide license to run one.
Nemechek, who also fields Toyotas, agreed to let Raikkonen drive his car that is guaranteed a spot in the field ranked 19th in owner's points.
Raikkonen said he had fun in the Truck race even though he got off to a rough start hitting the wall.
"I hit much harder and destroyed the car a little bit," the 2007 F1 champion said after the race. "The car actually ran really well there before the pit stop. Once we got to the pit then the tires and the tire pressure, it was better.
"For sure, there is still a lot to learn and improve, but I think when we have another race it will be better," he said.
There is also speculation Raikkonen will make his Sprint Cup debut next month at the road course in Sonoma, Calif. Cup driver Juan Pablo Montoya, Raikkonen's F1 teammate at McLaren until he left in 2006, said the Finnish driver needs to move to the United States and get in a Cup ride if he plans to make a commitment to NASCAR.
"If he's going to do it, he's got to do Cup like I did," Montoya said. "He's not a young guy who needs experience."
David Newton covers NASCAR for ESPN.com. He can be reached at firstname.lastname@example.org.