The highway meets the western end of Montrose Road shortly before entering the city of Rockville.

MD 189 expands to a four-lane divided highway ahead of its intersection with Wootton Parkway.

The highway continues through a single-point urban interchange with I-270 (Eisenhower Memorial Highway) shortly before reaching its northern terminus at a four-way intersection with Great Falls Road, Maryland Avenue, and Potomac Valley Road.

Great Falls Road (formerly a direct continuation of Falls Road, now a left turn at the intersection) heads north toward the west end of downtown Rockville and Maryland Avenue heads northeast directly toward downtown.

[7][8] As part of that project, MD 189 was expanded to a four-lane divided highway from south of Wootton Parkway to Maryland Avenue.