Section 436.1100 - Basis and scope(a)Statutory basis. Section 1920A of the Act allows States to provide Medicaid services to children under age 19 during a period of presumptive eligibility, prior to a formal determination of Medicaid eligibility.(b)Scope. This subpart prescribes the requirements for providing medical assistance to special groups who are not eligible for Medicaid as categorically or medically needy.