The jet was built in 2015, and Musk acquired it in 2016. It isn't Musk's first plane: The Tesla CEO also owns a Dassault Falcon 900B, which he bought in 2004.
Amazon mogul Jeff Bezos and soccer star Cristiano Ronaldo each also reportedly own a Gulfstream G650ER.
In an interview with Chris Anderson at the TED Conference in April, Musk said he doesn't spend "billions of dollars a year in personal consumption" — but that the jet is an exception to his frugal lifestyle. Musk added that he doesn't own a home, a yacht, or take vacations.
"I mean, the one exception is the plane, but if I don't use the plane then I have less hours to work," he said in the interview.
The plane, which is under the registration N628TS, was in Austin, Texas, on April 15, according to a Twitter account that's run by a teenager and tracks the location of Musk's jet.
Musk and Tesla did not immediately reply to Insider's requests for comment.