It runs for 0.70 miles (1.13 km) from the Connecticut state line, where it continues south into Greenwich as Riversville Road, to an intersection with NY 22 near the hamlet of Armonk.

NY 433 winds northward through a residential area of North Castle, passing the wooded Johnson Park on the southbound side of the highway.

The route winds northward past several intersections with local streets, soon reaching the junction with NY 22 (Armonk–Bedford Road).

This junction marks the northern terminus of NY 433, just 0.7-mile (1.1 km) north of the state line.

[4] It was extended southward to the Connecticut state line in the mid-1930s over NY 22 and North Greenwich Road.