Schools are required, by law, to provide services to students with special needs. Originally, the law which protected students with special needs was the Education for all Handicapped Children Act (or EHC) of 1975. In 1990, EHC was changed and named Individuals with Disabilities Education Act (IDEA). Within this law, the terminology of "handicapped child" was renamed "child with a disability."
Schools must adhere to the laws defined in IDEA. If a school does not adhere to this law, the school can be refused federal aid monies. Parents can also file suits against the teacher and school if they believe the rights of their child have been infringed upon.
Therefore, to insure that students with special needs are accommodated, schools usually have special education teachers and special education districts which help with examining each student's individual needs (put into an IEP--individual educational plan). Both special educations and general education teachers MUST adhere to the modifications laid out in each IEP. If the modifications laid out in the IEP are not made, the student's rights have been infringed upon.
Each school must examine the number of students with special needs in order to define how the types of programs the school must implement. Schools with a small number of students with special needs do not necessarily need to hire a whole team of special education teachers. In some cases, only one teacher would be necessary. In other cases, some districts have large numbers of students with special needs. In these cases, numerous special education teachers are required.
In other extreme cases, some schools have a large number of extreme cases of students of special needs. These schools will build special buildings (which house special equipment) for students with extreme disabilities. In cases like this, sometimes, other school districts will take advantage of this specialized learning environment and send their own students there.
Regardless of the individual modifications made by schools, all schools are required to meet the individual needs of any student with special needs.