Waterbury Hospital announced Tuesday that it would join a joint venture between St. Mary’s Hospital and a private Texas hospital group, moving forward with long-contemplated plans to merge the city’s two hospitals.

Under the planned joint venture, which must receive regulatory approval, both hospitals would be replaced by a new medical center, an investment of $400 million.

LHP Hospital Group, the private company, would own an 80 percent interest in the joint venture. Greater Waterbury Health Network and St. Mary’s Health System, the two hospitals’ parent companies, would each own 10 percent. All three would share governance, according to a statement from Waterbury Hospital.

Waterbury and St. Mary’s already collaborate in some areas, including the Harold Leever Regional Cancer Center and the Heart Center of Greater Waterbury.

The move follows the announcement in March that Yale-New Haven Hospital and the Hospital of St. Raphael will explore a merger that would create a single hospital with two campuses in New Haven. St. Mary’s and LHP announced their plans for a joint venture the same week, and have filed an application with the state Office of Health Care Access, which must approve the plan.

If both mergers take place, Hartford and Bridgeport will be the only Connecticut cities with two hospitals.

Arielle Levin Becker covered health care for The Connecticut Mirror. She previously worked for The Hartford Courant, most recently as its health reporter, and has also covered small towns, courts and education in Connecticut and New Jersey. She was a finalist in 2009 for the prestigious Livingston Award for Young Journalists, a recipient of a Knight Science Journalism Fellowship and the third-place winner in 2013 for an in-depth piece on caregivers from the National Association of Health Journalists. She is a 2004 graduate of Yale University.

Leave a comment