Michael Waltrip will honor and raise funds for Sandy Hook Elementary School in the No. 26 car at the Daytona 500.
The two-time Daytona 500 winner was set to drive the No. 30 Toyota in a one-race deal.
The number instead will be changed to No. 26 to honor the victims.
Sandy Hook is the school in Newtown, Conn., where 20 first-graders and six adults were killed by a gunman on Dec. 14.
The No. 26 car was at Daytona International Speedway on Thursday and had a black and green ribbon on the hood.
Waltrip also owns a team and all three entries will run with the "text NEWTOWN to 80888" decal for the Daytona 500 on Feb. 24.
NASCAR Brian France and Waltrip visited Newtown last week.