St. Joseph's Hospital Health Center, which lost $21.6 million in 2014, wants to join a large nonprofit health care system. St. Joe's has signed a non-binding preliminary agreement to join an unnamed health organization. If the deal goes through, it will help St. Joe's sustain its mission, the hospital disclosed in its unaudited 2014 financial results posted on the Electronic Municipal Market Access website. The hospital announced plans in 2013 to join Trinity Health, a national Catholic system that operates hospitals and other facilities in 21 states. St. Joe's and Trinity dropped that plan three months later for undisclosed reasons. But last year St. Joe's entered into an affiliation with Trinity.