MD 28 heads southeast and crosses the Monocacy River at Furnace Ford shortly before entering Montgomery County. After intersecting Mouth of Monocacy Road, which heads west to the Monocacy Aqueduct, the state highway enters Dickerson, where the road meets Mt. Ephraim Road, which serves MARC's Dickerson station and continues northeast toward Sugarloaf Mountain. Immediately after Mt. Ephraim Road, MD 28 turns south and passes through a narrow underpass of the Metropolitan Subdivision rail line. MD 28 crosses the Little Monocacy River before the intersection with Martinsburg Road, which heads southwest toward the Dickerson Generating Station and White's Ferry.