Known as Fairhaven Road, the highway runs 2.79 miles (4.49 km) from MD 2 near Friendship east to Arundel Road at Fairhaven in southern Anne Arundel County.

MD 423 was constructed in the early 1930s and extended at its western end in the late 1950s.

The state highway turns south and parallels the shore of Herring Bay.

MD 423 crosses an inlet of Herring Bay before reaching its eastern terminus at Arundel Road in the hamlet of Fairhaven.

[3][4] The highway was extended south to its present terminus at Fairhaven in 1931 and 1932.