The first phase of the Second Avenue Subway is three-quarters of the way done now that construction crews have finished the shell for the 86th Street station, the MTA announced Thursday.

Excavating the bedrock, installing concrete lining and utility work took more than three years and $332 million to finish, bringing the entire first phase of the Second Avenue subway to 76% complete.

The station now needs heating, ventilation and air conditioning work, elevator and escalators and architectural finishes.

MTA officials this week said the new subway line that will bring the Q train up Second Avenue to 96th Street is still slated to be ready for service December 2016.