Psychological evaluations include tests for intelligence, adaptive skills, and academic performance in reading, mathematics, written expression and spelling. Assessments for autism, anxiety, depression, social communication, learning, attention and other functions of the brain and behavior can be performed as needed.

Psychological evaluations can be performed by clinical psychologists and are for the purpose of getting the medical diagnosis of ID. In many cases the medical diagnosis is provided by a team, which may also include a physician, occupational therapist, and speech pathologist. A medical diagnosis is required by medical insurance for coverage for services and interventions provided outside school.

Psychological tests can also be performed by a school/educational psychologist for the purpose of getting an educational diagnosis, which is used to qualify for intervention services through school.

Medical evaluations are usually performed by a physician specialized in development and behavior, such as a developmental behavioral pediatrician. The evaluation consists of medical, developmental, behavioral, educational and family history, as well as a physical examination. The physician will review previous evaluations and will also perform a developmental and behavior assessment. The medical evaluation can provide the medical diagnosis of DD/ID, as well as other behavioral and communication conditions that may occur together with intellectual disability, such as autism or Attention Deficit Hyperactivity Disorder (ADHD).

During these evaluations, children will also be assessed for medical conditions which can be seen more frequently in children with DD/ID, such as constipation, abnormal weight gain, hearing, vision, sleep and feeding disorder, pica (eating non-food items), seizures, teeth and gum problems.

Children with DD/ID may need to be referred for audiological (hearing) and ophthalmological (eye and vision) assessments. As part of the medical evaluation, the physician may recommend different blood tests, such as genetic testing, lead toxicity screening and thyroid function. In some children, a brain MRI (special picture of the brain) or EEG (a brain wave study to check for seizures) may also be done.

These are some of the specialists who may be helpful in evaluating and following children with DD/ID: