For the purpose of this subchapter, the terms “low income families or persons” and “very low-income families or persons” means those families and persons whose incomes do not exceed the respective levels established for lower income families and very low-income families under the United States Housing Act of 1937 [ 42 U.S.C. 1437 et seq.]. Notwithstanding the preceding sentence, the maximum income levels established for purposes of this subchapter for such families and persons in the Virgin Islands shall not be less than the highest such levels established for purposes of this subchapter for such families and persons in American Samoa, Guam, the Northern Mariana Islands, and the Trust Territory of the Pacific Islands. The temporary absence of a child from the home due to placement in foster care should not be considered in considering family composition and family size.