20 C.F.R. § 219.55 Evidence of school attendance for child age 18.
Title 20 - Employees' Benefits
The child will be asked to submit (on a form furnished by the Board or other form acceptable to the Board) the following evidence: (a) A signed statement that he or she is attending school full-time and is not being paid by an employer to attend school; and (b) A statement from an official of the school verifying that the child is attending school full-time. The Board may also accept as evidence a letter of acceptance from the school, receipted bill, or other evidence showing that the child has enrolled or been accepted at that school or is continuing in full-time attendance.
Title 20: Employees' Benefits
PART 219—EVIDENCE REQUIRED FOR PAYMENT
Subpart D—Other Evidence Requirements
§ 219.55 Evidence of school attendance for child age 18.