He was the Republican nominee for New York State Comptroller in 2014, losing to incumbent Democrat Tom DiNapoli.

In 2019, Antonacci was elected as a Justice of the New York Supreme Court—a trial-level court—in the Fifth Judicial District and stepped down from his Senate seat.

[11] Four years later, after no other candidates came forward, he accepted the Republican nomination for the 2014 New York Comptroller election, anticipating that he would receive matching funds for his campaign.

[12] He failed to raise enough money to qualify for matching funds under the state's pilot program and lost to incumbent Thomas DiNapoli.

[15] Democrats targeted the district as a prime pickup opportunity, lining up behind the candidacy of public school teacher John Mannion.