(Reuters) - A coalition of hospitals has sued the U.S. government, claiming that the healthcare program for military personnel systematically underpaid the hospitals for outpatient services over a period of six years. Michigan-based Ingham Regional Medical Center and four other community hospitals filed the proposed class action on Monday on behalf of 1,700 hospitals around the country that provided medical care to military personnel and their dependents between 2003 and 2009. The lawsuit, filed in U.S. District Court for the District of Columbia, names newly appointed Secretary of Defense Charles Hagel, the official operator of the TRICARE program, as the sole defendant.