MD 118 is the four- to six-lane main highway through the central Montgomery County community of Germantown.

The route expands to a six-lane divided highway just south of its intersection with MD 117 (Clopper Road).

MD 118 continues northeast and meets the southern end of Father Hurley Boulevard, which serves the northwestern part of Germantown, then crosses over CSX's Metropolitan Subdivision railroad line next to the Germantown station on MARC's Brunswick Line.

Germantown Road continues east as a two-lane undivided county highway toward Montgomery Village.

[4] The macadam road was extended south to what is today the MD 117 intersection in what was called Old Germantown in 1923.

[13] The second step was completed in 1998; MD 118 was extended from Wisteria Drive along a new divided highway alignment that crossed a new bridge across the railroad tracks and reconnected with the old road at the southern end of divided highway south of MD 117.