Muscoy is a census-designated place (CDP) in San Bernardino County, California, United States. The population was 10,644 at the 2010 census, up from 8,919 at the 2000 census. Muscoy shares ZIP code 92407 with the communities of Verdemont, Devore Heights, Rosena Ranch and Arrowhead Farms in northwestern San Bernardino. Residents enjoy a semi-rural setting with large lots where they can raise horses and other livestock, nursery plants, and fruit trees. For this reason, much of Muscoy is included in the county Additional Agriculture (AA) overlay, which specifies the types and quantities of animals that may be kept on each parcel. A distinctive feature of Muscoy life today is motor vehicles and equestrians sharing the roadways.