In Greenport, maintenance of NY 23B reverts to the New York State Department of Transportation (NYSDOT). The route remains in Greenport for only , passing residential and industrial neighborhoods on the fringe of the city as it intersects the north end of County Route 29 (Spook Rock Road). Just east of the junction, NY 23B traverses Claverack Creek and crosses into the town of Claverack, where the route initially serves a sparsely developed area between the town line and the hamlet of Claverack-Red Mills. The open fields are gradually replaced by homes as the highway enters Claverack, where NY 23B meets NY 9H and NY 23 at a junction in the center of the community. NY 23B ends here while NY 23 continues east on the route's right-of-way.