 PA 73 crosses into Douglass Township in Montgomery County and continues along East Philadelphia Avenue into commercial areas, widening into a four-lane divided highway as it reaches an interchange with PA 100.Past this interchange, the route becomes a three-lane road with a center left-turn lane and passes a mix of homes and businesses in the community of Gilbertsville.PA 73 narrows to two lanes and continues to an intersection with Swamp Pike and Gilbertsville Road, at which point it turns east to remain along East Philadelphia Avenue and runs past residential subdivisions.