[1] From 1963 to 1970, Bellacosa worked as a law clerk to New York State Appellate Division Justice Marcus G.
In April 1985, Bellacosa was appointed and confirmed to serve as a judge of the New York Court of Claims.
[3] On January 5, 1987, Governor Mario Cuomo nominated Bellacosa to fill the seat of Justice Bernard S. Meyer on the New York Court of Appeals.
[1][4] A political independent, Bellacosa was noted for his conservative decision while serving on the bench, specifically in areas such as prosecutors' rights, and had a tendency to defer to the judiciary.
[4] After retiring, Bellacosa became the Dean of his alma mater, the St. John's University School of Law, from July 2000 to August 2004.