OPEN MINDS, The Behavioral Health & Social Service Industry Analyst Industry News Magellan Behavioral Health Inc. became the new behavioral health care provider for AmeriHealth Mercy Health Plan enrollees in Lancaster County, Pennsylvania, as of September 1, 1998. AmeriHealth Mercy provides health care services to Lancaster County's Medicaid recipients who are voluntarily enrolled. The Lancaster County Mental Health/Mental Retardation program had been the behavioral health provider for AmeriHealth Mercy from April 1994 until September 1998, when Magellan assumed responsibility. Magellan also is AmeriHealth Mercy's subcontractor for similar services . . .