LaJoie was also placed on indefinite probation Wednesday.
NASCAR did not refer to the since-deleted Oct. 15 tweet, by penalized LaJoie for "an insensitive and intolerable communication." The tweet suggested TSA should conduct a cavity search of a man wearing a turban.
The 22-year-old LaJoie said in a statement "it was an immature and insensitive comment. I'm upset with myself and how this has affected what has been a very positive year in my career."
LaJoie competes in the NASCAR K&N East Series and ARCA. He is expected to run some Nationwide Series races next season.
RPM this week fired crew chief Todd Parrott for failing a random NASCAR drug test.