Known as Lineboro Road, the state highway runs 4.00 miles (6.44 km) from MD 30 in Manchester north to the Pennsylvania state line in Lineboro, where the highway continues as Pennsylvania Route 516 (PA 516).

MD 86 heads northeast as a two-lane undivided road through farmland just south of the parallel Dug Hill Ridge and north of a tributary of the South Branch of Gunpowder Falls.

The state highway continues northeast as the main street of the village of Lineboro.

MD 86 crosses over the North Branch of Gunpowder Falls and heads across CSX's Hanover Subdivision railroad line at-grade while passing through the Lineboro Historic District.

[5] MD 86 was completed as a concrete road through Lineboro to the Pennsylvania state line in 1929 and 1930.