Jefferson Health is expanding its operations at the 95,000-square-foot Three Crescent Drive office building at the Navy Yard in South Philadelphia to become the building's dominant tenant.

The health system will open a new 70,000-square-foot adult health and  wellness facility in the building by mid-2018, it said in a release Friday.

The expansion will bring Jefferson's total occupancy at Three Crescent Drive up to about 80,000 square feet, according to Navy Yard developer Liberty Property Trust. It will include space vacated by the Philadelphia 76ers, Tasty Baking Co. and Penn Capital Management, which moved and expanded into the Navy Yard's recently completed 1200 Intrepid Ave. building, said Brian Cohen, a Liberty vice president.