55 Pa. Code § 3140.102
The following words and terms, when used in this subchapter, have the following meanings, unless the context clearly indicates otherwise:
Child—An individual who is:
(ii) Eighteen years of age but not yet 19 years of age and a full-time high school or vocational or technical school student and expected to complete school before reaching the age of 19.
Placement maintenance—Payment for the allowable costs of substitute care provided to a child eligible for benefits under Title IV-E of the Social Security Act (42 U.S.C.A. § § 670—676).
Substitute care—
(1) Placement of a child outside of the home in either a:
(2) The term does not include a:
This section cited in 55 Pa. Code § 3140.111 (relating to county agency responsibilities).