ERIC Identifier: ED429396
Publication Date: 1998-04-00
Author: Knoblauch, Bernadette - Sorenson, Barbara
Source: ERIC Clearinghouse on Disabilities and Gifted Education Reston VA.

IDEA's Definition of Disabilities. ERIC Digest E560.

During 1995-1996, 5,796,833 children in the United States ages 0-21 received special education and related services under IDEA, Part B and Part H.


The Education for All Handicapped Children Act (P.L. 94-142) of 1975 and the Individuals with Disabilities Education Act (IDEA) (P. L. 101-476) identified specific categories of disabilities under which children may be eligible for special education and related services. As defined by IDEA, the term "child with a disability" means a child: "with mental retardation, hearing impairments (including deafness), speech or language impairments, visual impairments (including blindness), serious emotional disturbance, orthopedic impairments, autism, traumatic brain injury, other health impairments, or specific learning disabilities; and who, by reason thereof, needs special education and related services."

The most recent legislation, the IDEA Amendments of 1997 (P.L. 105-17), allows states and local education agencies to apply the term "developmental delay" for children ages 3-9. Previously, this definition applied to children ages 3-5. "For children ages 3 through 9, the term 'child with a disability' may, at the discretion of the state and the local education agency, include children who are experiencing developmental delays in one or more of the following areas: physical development, cognitive development, communication development, social or emotional development, or adaptive development...."

Thus, children must meet two criteria in order to receive special education: (1) the child must have one or more of the disabilities listed below, and (2) he or she must require special education and related services. Not all children who have a disability require special education; many are able to and should attend school without any program modifications. Following are the disabilities included in the definition.

Autism: A developmental disability significantly affecting verbal and nonverbal communication and social interaction, generally evident before age 3, that adversely affects a child's educational performance. Other characteristics often associated with autism are engagement in repetitive activities and stereotyped movements, resistance to environmental change or change in daily routines, and unusual responses to sensory experiences. The term does not apply if a child's educational performance is adversely affected primarily because the child has a serious emotional disturbance as defined below. Autism was added as a separate category of disability in 1990 under P.L. 101-476. This was not a change in the law so much as it is a clarification. Students with autism were covered by the law previously, but now the law identifies them as a separate and distinct class entitled to the law's benefits.

Deafness: A hearing impairment so severe that the child cannot understand what is being said even with a hearing aid.

Deaf-Blindness: A combination of hearing and visual impairments causing such severe communication, developmental, and educational problems that the child cannot be accommodated in either a program specifically for the deaf or a program specifically for the blind.

Hearing impairment: An impairment in hearing, whether permanent or fluctuating, that adversely affects a child's educational performance but that is not included under the definition of deafness as listed above.

Mental retardation: Significantly subaverage general intellectual functioning existing concurrently with deficits in adaptive behavior. And manifested during the developmental period that adversely affects a child's educational performance.

Multiple disabilities: A combination of impairments (such as mental retardation-blindness, or mental retardation-physical disabilities) that causes such severe educational problems that the child cannot be accommodated in a special education program solely for one of the impairments. The term does not include deaf-blindness.

Orthopedic impairment: A severe orthopedic impairment that adversely affects educational performance. The term includes impairments such as amputation, absence of a limb, cerebral palsy, poliomyelitis, and bone tuberculosis.

Other health impairment: Having limited strength, vitality, or alertness due to chronic or acute health problems such as a heart condition, rheumatic fever, asthma, hemophilia, and leukemia, which adversely affect educational performance.

Serious Emotional Disturbance: A condition exhibiting one or more of the following characteristics, displayed over a long period of time and to a marked degree that adversely affects a child's educational performance:

* An inability to learn that cannot be explained by intellectual, sensory, or health factors

* An inability to build or maintain satisfactory interpersonal relationships with peers or teachers

* Inappropriate types of behavior or feelings under normal circumstances

* A general pervasive mood of unhappiness or depression

* A tendency to develop physical symptoms or fears associated with personal or school problems.

This term includes schizophrenia, but does not include students who are socially maladjusted, unless they have a serious emotional disturbance. P.L. 105-17, the IDEA Amendments of 1997, changed "serious emotional disturbance" to "emotional disturbance." The change has no substantive or legal significance. It is intended strictly to eliminate any negative connotation of the term "serious."

Specific Learning Disability: A disorder in one or more of the basic psychological processes involved in understanding or in using language, spoken or written, that may manifest itself in an imperfect ability to listen, think, speak, read, write, spell, or do mathematical calculations. This term includes such conditions as perceptual disabilities, brain injury, minimal brain dysfunction, dyslexia, and developmental aphasia. This term does not include children who have learning problems that are primarily the result of visual, hearing, or motor disabilities; mental retardation; or environmental, cultural or economic disadvantage.

Speech or language impairment: A communication disorder such as stuttering, impaired articulation, language impairment, or a voice impairment that adversely affects a child's educational performance.

Traumatic brain injury: An acquired injury to the brain caused by an external physical force, resulting in total or partial functional disability or psychosocial impairment, or both, that adversely affects a child's educational performance. The term applies to open or closed head injuries resulting in impairments in one or more areas, such as cognition; language; memory; attention; reasoning; abstract thinking; judgment; problem-solving; sensory, perceptual and motor abilities; psychosocial behavior; physical functions; information processing; and speech. The term does not apply to brain injuries that are congenital or degenerative, or brain injuries induced by birth trauma. As with autism, traumatic brain injury (TBI) was added as a separate category of disability in 1990 under P.L. 101-476.

Visual impairment, including blindness: An impairment in vision that, even with correction, adversely affects a child's educational performance. The term includes both partial sight and blindness.


Children suspected of having a disability are evaluated by a multidisciplinary team that includes at least one teacher or other specialist with knowledge in the area of the suspected disability. Following a full individual evaluation of the child's educational needs, the team determines whether or not the child requires special education and related services. If the evaluation confirms that a child has one or more disabilities and requires special education and related services because of the disabilities, then states and localities must provide a free, appropriate public education for that child.

The new IDEA (P. L. 105-17) sends a strong message about the school's responsibility to include students with disabilities in the general education classroom and curriculum, with accommodations when necessary; " be involved and progress in the general curriculum...and to participate in extracurricular and other nonacademic activities; be educated and participate with other children with disabilities and nondisabled children..."[Section 614(d)(1)(A)(iii)]. Schools may place children with disabilities in separate classrooms or schools only when supports and services are not enough to help the child learn in a regular classroom.


Final Regulations for Part B of IDEA, 57 C.F.R. 300.7 (1992).

Individuals with Disabilities Education Act Amendments of 1997 (P.L. 105-17), 111 Stat. 37-157 (1997).

Nineteenth Annual Report to Congress on the Implementation of the Individuals with Disabilities Act. (1997). (ED412721). ERIC Document Reproduction Service (EDRS), 7420 Fullerton Road, Suite 110, Springfield, VA 22153-2852. 800-443-3742. 381pp.


Davis, W. E. (1986). Resource guide to special education. Allyn and Bacon, Inc., 160 Gould St., Needham Heights, MA 02194. 317pp.

Rothstein, L. F. (1995). Special education law. Longman Publishers USA, 10 Bank Street, White Plains, NY 10606. 396pp.

Turnbull, H. R. III. (1993). Free appropriate public education: The law and children with disabilities. Love Publishing Company, 1777 South Bellaire St., Denver, CO 80222. 389pp.

U.S. Department of Education, Office of Special Education and Rehabilitative Services. (1992). Summary of existing legislation affecting people with disabilities. (ED355701). ERIC Document Reproduction Service (EDRS), 7420 Fullerton Road, Suite 110, Springfield, VA 22153-2852. 800-443-3742. 235pp.

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