Until 1991, this area shared a mailing address and ZIP Code (10566) with the city of Peekskill. Although it now has its own ZIP code, 10567, many directories and censuses still do not include Cortlandt Manor, because it is unincorporated. The term "Cortlandt Manor" was created by the US Postal Service to differentiate this part of Corlandt town from Cortland, New York, which is located hours away. Many longtime residents of the Town of Cortlandt consider the new name to be a vanity invention to protect the home values of Cortlandt residents who resented a Peekskill mailing address, though this motivation is not expressed in any official record of the decision.
Cortlandt Manor residents are served by Hendrick Hudson Central School District, Lakeland Central School District, and Putnam Valley Central School District. Two schools in Hendrick Hudson Central School District are located in Cortlandt Manor: Furnace Woods Elementary School and Blue Mountain Middle School, which are separated by several soccer fields. Two of the Lakeland Central School District schools are located in Cortlandt Manor: Van Cortlandtville Elementary School and Walter Panas High School.