Johnson announced in December he would compete in the full 2022 IndyCar season and had a best finish of fifth at the Grand Prix of Iowa in July.
"I couldn’t have asked for a better experience in the @Indycar series," Johnson tweeted. "I will not return to INDYCAR full time in 2023 but will continue to look for new ways to challenge myself and participate in bucket list events."
Johnson is widely considered among the greatest NASCAR drivers of all time, having won a record five consecutive NASCAR Cup Series Championships from 2006 to 2010.
His seven total titles puts him level with Richard Petty and Dale Earnhardt for the record.
The jump to IndyCar was one other drivers from Mario Andretti to Jacques Villeneuve and Romain Grosjean have made in the past.
"I feel like I have improved but I realize the challenge is about two, three times greater than what I first thought," he said in a video posted to YouTube.
"I don't want to enter another full season if I know I can't give it my all. But I'd love to go back and do it again."
He added he would take time to "let the dust settle" from 2022. "I'm just going to take a little bit of time to think, to figure out what I want to do," he said.
