Rush University System and Endeavor Health announce merger, would create largest health system in Chicago. Rush University System for Health and Endeavor Health announced they will merge into a single integrated academic health system, creating the largest health system in Chicago. The combined system will have 12 award-winning hospitals and more than 400 care sites, the merger announcement said. The announcement said a "significant portion" of that investment will be spent on community partnership to address "social determinants of health" and creating infrastructure to support underserved patients and communities. The combined health system will operate under the Rush name, officials said. Rush University System is a nonprofit health system including Rush University Medical Center, Rush University, Rush Copley Medical Center and Rush Oak Park Hospital. Endeavor is Illinois' third-largest health system based in the Chicago area and serving seven northeast Illinois counties. Rush and Endeavor said they expect to complete the merger in early 2027 after regulatory review and approval. #### CBS News Chicago.