CHICAGO (AP) — Illinois-based Advocate Health Care and Wisconsin-based Aurora Health Care say they plan to merge.

The organizations announced the merger Monday. They say the new system, Advocate Aurora Health, would serve almost 3 million patients annually at 27 hospitals and more than 500 other sites and would be the 10th largest non-profit hospital system in the U.S.

Dr. Nick Turkal is president and CEO of Aurora Health Care. Turkal says calls the plan “an unprecedented opportunity to shape our future and better serve patients.”

The merger needs approval from state regulatory agencies in Illinois and Wisconsin and the Federal Trade Commission.