The donation will be added to IMA's endowment of $367 million, but interest proceeds will fund salary and professional development expenses for the museum's head.
Though several large art museums have endowed directorships, the Simons' gift will be the largest ever given to underwrite the top position, according to the IMA.
In recognition of the donation, the position now will be called the Melvin & Bren Simon Director and CEO. Director Maxwell Anderson will be the first to serve with that title but the endowment-and lengthy title-will continue.
The gift is just the first step in the museum's strategic goal to endow several key department positions.
"We hope our gift will help shine a national spotlight on our city's arts and cultural offerings just as much as our rich traditions in sports," Bren Simon said in a statement. The couple also co-owns the Indiana Pacers.