Danica Patrick won't be back with Stewart-Haas Racing next season after five years with the NASCAR team.
The 35-year-old Patrick had one season left on her contract. Stewart-Haas Racing hasn't yet announced a replacement driver.
Patrick confirmed her departure on a Facebook post.
"It has been my honor to drive for Tony Stewart, Gene Haas and everyone at Stewart-Haas Racing. Together we earned a Daytona 500 pole, seven top-10 finishes and we also had some exciting racing along the way. My time driving for them, however, has come to an end due to a new sponsorship arrangement in 2018.
"... I wish SHR the best of luck with their new sponsorship and driver. Thanks for the memories. Right now, my focus is on the remainder of the 2017 season and finishing the year strong. I have the utmost faith in myself and those around me, and feel confident about my future."
Patrick had a disappointing 2017 season and is 28th in the points standings.
Patrick spent seven years as an IndyCar driver before making the move to NASCAR in 2012. Her best finish in a NASCAR race was when she placed sixth in Atlanta in 2014.
Here lone IndyCar victory was in 2008 at a race in Japan. She also finished third in the 2009 Indianapolis 500.