AdventHealth’s St. Johns ambitions extend beyond ER opening (Courtesy of the Jacksonville Business Journal) — Driving down Interstate 95, it’s hard to avoid spotting AdventHealth signage. That’s the sort of visibility its leaders want in St. Johns County.
The Central Florida-based healthcare system will officially open its standalone emergency room in St. Johns County on Friday. It will mark the first time patients will be cared for at a ground-up constructed AdventHealth facility in Northeast Florida.
“Our goal, five years from now, I think people are going to hopefully not remember when AdventHealth wasn’t in St. Johns County because we’ll be such a part of that community,” East Florida Division President and CEO Rob Deininger told the Business Journal.
Headquartered in Altamonte Springs, AdventHealth’s footprint extends across 32 hospitals and hundreds of care facilities in Florida. More recently, Northeast Florida became its latest new market target.
The faith-based nonprofit doesn’t dip a toe into new markets. Instead, it expands with purpose.
Those roots begin with the St. Johns freestanding facility, called Treaty Oaks ER. The building spans 16,116 square feet on 11 acres at 1775 State Road 207. Initially securing a $12 million permit for construction in August last year, the facility is expected to create 56 jobs and generate $5.5 million in economic impact. Alabama-based Robins & Morton, a privately-held construction firm, worked on the project.
Expanding from AdventHealth’s extensive operations in neighboring Flagler County was a no-brainer for the institution.
The county is an “extremely attractive market” for AdventHealth, Deininger said, but it has very low market penetration. Typically, he said, growing to new markets begins with offsite emergency departments and doctors’ offices, which both establish the brand.
Long before Friday’s opening, that strategy was already at play.
In November 2025, AdventHealth unveiled a 3,000-square-foot specialty clinic in St. Augustine. Centered around specialized care in cardiology, gastroenterology, orthopedics and neurosurgery, among others, the office was built out at 1000 Plantation Drive.
Elsewhere, development isn’t fully finalized yet, but the system also bought three parcels of land in the World Golf Village area for $13.14 million in February 2025.
Phase one of that property is anticipated to include a 12-bed, 16,330-square-foot emergency room, associated parking, helipad and “infrastructure to serve a future hospital and two future medical office buildings,” according to an application submitted to the county’s Development Review Committee, a preliminary planning board, in March of this year.
“It’s part of us beginning to put a strategy together for the entirety of the county,” Deininger said of all three projects.