"#back@work! So grateful today! :)" she wrote Wednesday, alongside a photo of herself.
Although she offered no details about what she is working on this week, HBO told E! News Lohan has been booked to guest-star on the upcoming fourth and final season of its Danny McBride-starring sitcom "Eastbound and Down."
The eight-episode season is to kick off Sept. 29.
Notable deaths of 2014 [PHOTOS]