In 1979, ground was broken for necessary new facilities. The new hospital opened as the first all private-room hospital in Northeast Wisconsin in the fall of 1981.
The Family Birthing Center was added in 1988 as well as an enlargement and renovation of St. Mary's Emergency Center.
In July 1989, HSHS St. Mary's Hospital Medical Center and HSHS St. Joseph's Hospital of Chippewa Falls opened Libertas, a 24-bed inpatient facility for chemically dependent adolescents on the HSHS St. Mary's Hospital Medical Center campus.
In 1992, a major ambulatory wing was added including outpatient surgery, advanced radiology and diagnostic services, respiratory care, pulmonary medicine and a new education center. Many doctors at HSHS St. Mary's Hospital Medical Center enjoy the convenience of a connected office complex that features modern services, dedicated parking and a private entrance. This part of the campus was developed during the 1990s and currently is home to more than 40 medical providers.