Columbia Grammar & Preparatory School ("Columbia Grammar", "Columbia Prep", "CGPS", "Columbia") is the oldest nonsectarian independent school in New York City, located on the Upper West Side of Manhattan (5 West 93rd Street). The school serves grades Pre-kindergarten to 12 and offers a college preparatory curriculum. The school dissolved its formal ties with Columbia in 1865. The word "preparatory" was added in 1969.