As of this week, Chicagoans visiting any of the 56 health care clinics in Walgreens throughout the region will be receiving care from a different organization.

Downers Grove-based Advocate Health Care, the largest health system in Illinois, has taken over the clinics. The management shift is billed as a “clinical agreement” and was first announced in January.

The change in ownership entails staffing the clinics with Advocate-trained nurses and medical assistants, and running them on Advocate’s electronic medical record system and billing software. The clinics now accept the same insurance Advocate-affiliated hospitals and clinics do, including Medicare, Medicaid and most major insurance plans. For uninsured individuals, the clinics offer an $89 flat fee for visits.

For Advocate, the takeover is an opportunity to expand its reach and target care toward underserved people who might not otherwise have the time or ability to visit a hospital, said Dr. Lee Sacks, executive vice president and chief medical officer of the health system.

“Even for those without insurance, an $89 visit for simple, uncomplicated medical conditions is a real attraction,” Sacks said. “As well as the extended hours — seven days a week — the ability to walk in and not have an appointment or to choose to schedule an appointment online rather than waiting.”

The clinics are equipped to provide care for a range of minor illnesses, including vaccinations, physicals, sore throats and other common acute conditions.

Max Green reports for the WBEZ news desk. Follow him @maxraphaelgreen