Known as White Marsh Boulevard, the state highway runs 8.65 miles (13.92 km) from Interstate 695 (I-695) near Parkville east to MD 150 in Middle River.

As MD 43 passes through the community of Fullerton, the highway has intersections with county-maintained Walther Boulevard and a pair of two-way quadrant ramps that connect the boulevard with either direction of US 1 (Belair Road), under which MD 43 passes between the pair of ramps.

[1][2] East of the town center, MD 43 veers away from Whitemarsh Run and meets I-95 (John F. Kennedy Memorial Highway) at an interchange; this interchange has full access to I-95 along with access to the southbound direction of the I-95 Express Lanes and from the northbound direction of the I-95 Express Lanes.

MD 43 curves southeast through a forested area with scattered industrial parks, where the highway crosses over Bird River Road and Windlass Run and intersects Crossroads Circle.

[6][7] Around 1983, in conjunction with the construction of White Marsh Town Center, the state highway's western terminus was moved to just east of the Honeygo Boulevard intersection, which became a three-way directional intersection with an overpass for traffic from westbound MD 43 south onto Honeygo Boulevard toward White Marsh Mall.

[14] The state highway was completed east to MD 150 on October 23, 2006, opening up a large area of eastern Baltimore County to commercial and industrial development.