Social Security has a strict definition of disability for children under the SSI program. A child who is underage 18 is disabled if he or she:

• Is not working at a job that we consider to be substantial work; and
• Has a physical or mental condition (or a combination of conditions) that results in “marked and severe functional limitations.”  This means that the condition(s) very seriously limits his or her activities; and
• The condition(s) has lasted, or is expected to last, at least 1 year or is expected to result in death.

To decide whether your child is disabled, we look at medical and other information (such as information from schools and from you) about his or her condition(s), and we consider how the condition(s) affects his or her daily activities.   We consider questions such as:

• What activities is your child not able to do, or is limited in doing?
• What kind of and how much extra help does your child need to perform age-appropriate activities — for example, special classes at school, medical equipment?
• Do the effects of treatment interfere with your child’s day-to-day activities?