AbelsonTaylor, a Chicago-based health and wellness advertising agency, will be the fourth confirmed tenant to move into Chicago’s Old Post Office. The 2.8 million-square-foot, Art Deco building is currently undergoing an $800 million facelift with the first tenants scheduled to move in by September.

AbelsonTaylor agreed to a long-term lease and will move from their current headquarters at 33 W. Monroe Street by next March 1.The 85,000-square-foot lease will allow the agency to grow its employee base—which currently numbers around 300—by a third, with 50 new hires expected this year.

“The Old Post Office continues to develop a diverse and progressive tenant base and the addition of AbelsonTaylor shows we are attracting tenants from all industries, including corporate headquarters, e-commerce, consumer products, media and advertising,” said Brian Whiting of The Telos Group LLC. “We could not be more excited that AbelsonTaylor will call The Old Post Office its new home and we appreciate their confidence in our vision for the building.”

New-York-based 601W Companies acquired the massive property, located at 433 W. Van Buren Street, in 2016 and tapped architecture firm Gensler to draw up a vision for the building’s second life, including the addition of a new food hall, a tenant-accessible rooftop and a new riverwalk. According to the Tribune, construction of the property’s amenity space, including a fitness center, conference rooms and lounges, are nearing completion.

Steve Smith, Jamey Dix and Daniel Heckman of the Telos Group represented 601W in this transaction. Jack Keenan of Cushman & Wakefield represented AbelsonTaylor.

Last month, the Chicago Metropolitan Agency for Planning signed a 15-year, 47,000-square-foot lease, following the December confirmation by Ferrara Candy that it would return to Chicago when and take on 77,000 square feet for 400 employees. Walgreens committed to more than 200,000 square feet inside the Old Post Office last June; approximately 1,800 employees will move into the building, though the company will retain its Deerfield, Illinois headquarters when the new office opens in the fall of 2019.