- Western Terminus:
- New York-Massachusetts state line
- Eastern Terminus:
- Westfield Road (US 20) in Russell
- 38.45 miles
- Berkshire, Hampden
MA 23 is an extension of NY 23 into the western half of Massachusetts. It begins at the state line and runs east to Great Barrington, where it is multiplexed with US 7 and MA 41 along Main Street through the downtown area. Then, it splits off to the east and crosses the Berkshire Mountains. On the other side, it reaches MA 8 in Otis. There is a short multiplex to the south, and then MA 23 splits off to continue east. It ends in Russell at Westfield Road (US 20) near the Massachusetts Turnpike (I-90), although there is no interchange in the area.