Cabin John-Brookmont was a census-designated place in Montgomery County, Maryland (adjacent to Washington, D.C.) during the 1980 and 1990 censuses, which included the primary communities of Cabin John and Brookmont. The population recorded in 1990 was 5,341 and consisted of 2,168 housing units. The census area disbanded to form Cabin John and Brookmont in 2000. The ZIP codes serving the area are 20816 and 20818.