Frank is the son of Henry (Len Cariou) and Betty Reagan, born in Bay Ridge, Brooklyn, New York in the mid-1950s. He had an older brother, Peter Christopher Reagan, who died of leukemia at the age of 18 months over a year before Frank was born. However, it is also mentioned that Frank does not have many friends in the New York City Council, especially after Danny's arrest of city Councilman Tony Mancini (Richard Burgi), a former NYPD detective, for domestic abuse.