Healy entered public service as an assistant prosecutor for the Hudson County Prosecutor's Office in 1977. From 1981 to 1991, he maintained a private law practice in Jersey City. He was appointed Chief Judge in the Jersey City Municipal Court in 1991, and was reappointed in 1995. In 1997, he ran unsuccessfully for Mayor of Jersey City against Bret Schundler, who later ran for Governor of New Jersey against Jim McGreevey. Healy resumed his private law practice until 2004, when he was elected mayor. Healy lost to Councilman Steven Fulop for mayor in 2013.