It begins at SR 89 in Caribou and runs east to U.S. Route 1A (US 1A) in Limestone.

It first heads northeast but curves to the south to cross the Little Madawaska River.

After exiting the city of Caribou towards the town of Limestone, SR 223 curves to the southeast before returning to an easterly heading.

Just east of Four Corners, SR 223 ends at US 1A, 1.5 miles (2.4 km) west of the Canadian border.

The highway followed entirely new routing from downtown to the current terminus at US 1A (then SR 165).