Grant is up to a series regular as the cranky Nurse Beverly on the Fox show about a physician (Mindy Kaling) who balances her career with her love life, reports TVLine.
Earlier this month, the show brought Mary Grill into the mix as Kaling's "tomboyish, confident, party" college friend Maggie.
Back in November, it was announced that Hal Linden is making a guest appearance on the sitcom as a "former Army drill sergeant".
Grant previously appeared Criminal Minds, Dexter and Modern Family.
The Mindy Project airs on Tuesdays at 9.30pm ET on Fox.
Watch a trailer for The Mindy Project below: