- Western Terminus:
- NY 26 in Cincinnatus
- Eastern Terminus:
- New York-Massachusetts state line
- 156.04 miles
- Cortland, Chenango, Otsego, Delaware, Schoharie, Greene, Columbia
NY 23 is an east/west route through the Catskills and the Hudson Valley to Massachusetts. It begins at NY 26 in Cincinnatus, a few miles east of I-81, and runs east to Oneonta, where it is multiplexed with NY 7 and NY 28 for a short distance, passing through an interchange with I-88. It continues east across the Catskills to Cairo, where it widens to become a four-lane divided highway. There are a couple of grade-separated interchanges, including with the New York Thruway (I-87) and US 9W. It then narrows back to two lanes and crosses the Hudson River via the Rip Van Winkle Bridge. On the other side of the river, it continues east across Columbia County to the border with Massachusetts, where it becomes MA 23.