The Federal Definition of Developmental Disabilities

The current definition under the DD Act[9] (adopted in 2000) defines “developmental disability” as a severe, chronic disability of an individual that:

• “(i) is attributable to a mental or physical impairment or combination of mental and physical impairments;
• (ii) is manifested before the individual attains age 22;
• (iii) is likely to continue indefinitely;
• (iv) results in substantial functional limitations in 3 or more of the following areas of major life activity:
  • (I) Self-care.
  • (II) Receptive and expressive language.
  • (III) Learning.
  • (IV) Mobility.
  • (V) Self-direction.
  • (VI) Capacity for independent living.
  • (VII) Economic self-sufficiency; and
• (v) reflects the individual’s need for a combination and sequence of special, interdisciplinary, or generic services, individualized supports, or other forms of assistance that are of lifelong or extended duration and are individually planned and coordinated.”