(a) Infant or toddler with a disability means an individual under three years of age who needs early intervention services because the individual—

(1) Is experiencing a developmental delay, as measured by appropriate diagnostic instruments and procedures, in one or more of the following areas:

(i) Cognitive development.

(ii) Physical development, including vision and hearing.

(iii) Communication development.

(iv) Social or emotional development.

(v) Adaptive development; or

(2) Has a diagnosed physical or mental condition that—

(i) Has a high probability of resulting in developmental delay; and

(ii) Includes conditions such as chromosomal abnormalities; genetic or congenital disorders; sensory impairments; inborn errors of metabolism; disorders reflecting disturbance of the development of the nervous system; congenital infections; severe attachment disorders; and disorders secondary to exposure to toxic substances, including fetal alcohol syndrome.

(b) Infant or toddler with a disability may include, at a State's discretion, an at-risk infant or toddler (as defined in § 303.5).

(c) Infant or toddler with a disability may include, at a State's discretion, a child with a disability who is eligible for services under section 619 of the Act and who previously received services under this part until the child enters, or is eligible under State law to enter, kindergarten or elementary school, as appropriate, provided that any programs under this part must include—

(1) An educational component that promotes school readiness and incorporates pre-literacy, language, and numeracy skills for children ages three and older who receive part C services pursuant to § 303.211; and

(2) A written notification to parents of a child with a disability who is eligible for services under section 619 of the Act and who previously received services under this part of their rights and responsibilities in determining whether their child will continue to receive services under this part or participate in preschool programs under section 619 of the Act.