Gwinnett Medical Center and its sister facilities are officially coming under the Northside Hospital umbrella Aug. 28, creating a Georgia health care behemoth with 21,000 employees and 250 outpatient locations.

After years of trying, the systems got the federal government's approval for the transaction earlier this year. Although it's called a merger, Northside Hospital is the giant in the deal and promised to pay hundreds of millions of dollars for the acquisition.

A spokeswoman for Northside, Katherine Watson, said that Gwinnett patients would see few changes, and that the Gwinnett hospitals would remain in the same insurance networks. She said patients should double-check with their insurance companies to confirm coverage.

The combined system will be called the Northside Hospital system. The flagship Gwinnett Medical Center in Lawrenceville will be renamed Northside Hospital Gwinnett, and the Duluth location of GMC will be Northside Hospital Duluth.

The Gwinnett extended care facility will be Northside Gwinnett Extended Care Center, and the Gwinnett rehabilitation facility will be Northside Gwinnett Joan Glancy.

Prior to the Georgia attorney general giving his approval in 2017, Northside agreed to invest $500 million into the Gwinnett system over 10 years, and to satisfy its debts, then about $275 million, Gwinnett officials testified. A spokeswoman for Northside did not confirm the final numbers Wednesday but said Northside would pay off all Gwinnett debt by Aug. 28.

The big question is whether prices will rise for patients. That often happens when hospitals consolidate, though research isn’t conclusive. This deal leaves four big health systems competing against each other in metro Atlanta, and fewer competitors overall. A fifth system, Childrens Healthcare of Atlanta, does not compete with the others for adult patients. The last independent hospital in metro Atlanta, DeKalb Medical Center, went under Emory’s management last year.

The expanded Northside Hospital system will have 1,636 inpatient beds and 3,500 physicians on staff. Debbie Mitcham, the chief financial officer for the Northside Hospital system, will replace the CEO of the Gwinnett locations, who will retire.

“Patients of the Gwinnett Health System will notice virtually no changes in their regimen of treatment and care,” the system announced in a statement, and they are working to combine seamlessly.