In 1948, a New York State law called the Intermediate School District Act gave the go-ahead for certain small school districts to combine their purchasing power, thus forming the first BOCES. By sharing the costs of services and programs through the BOCES, the districts could now assure high quality programs for students while saving their taxpayers money.

School districts are not required to use any BOCES programs or services. They choose to purchase a BOCES service rather than providing it on their own when they believe that the cost and quality warrant it. (In this sense, a BOCES resembles a business more than a public school district, though the BOCES are not organized for profit.) If a member district determines that it can provide the service better and/or for less money on its own, the district is free to do so.

When two or more districts within a BOCES identify a need (for example, special educational classes) it is the responsibility of their BOCES to help them fill the need. In this way, new BOCES programs and services are created at the request of member districts.

Member districts share the cost of the services in which they participate. Each district pays a percentage of the total cost, based on how much service it purchases. The more school districts that participate, the lower the cost for everyone.