the Public Health Service Act. (VIII) Seasonal employees. (IX) Employees who are nonresident aliens and who receive no earned income (within the meaning of section 911(d)(2)) from the employer which constitutes income from sources within the United States (within the meaning of section 861(a)(3)). (X) Such other classes of employees as the Secretary may designate. An employer may designate (in such manner as is prescribed by the Secretary) two or more of the classes described in the preceding subclauses as the specified class of employees to which the arrangement is offered for purposes of applying this subparagraph. (iii) Special rule for new hires An employer may designate prospectively so much of a specified class of employees as are hired after a date set by the employer. Such subclass of employees shall be treated as the specified class for purposes of applying clause (i). (iv) Rules for determining type of employee For purposes for clause (ii), any determination of full-time, part-time, or seasonal employment status shall be made under rules similar to the rules of section 105(h) or 4980H, whichever the employer elects for the plan year. Such election shall apply with respect to all employees of the employer for the plan year. (v) Permitted variation For purposes of clause (i)(I), an arrangement shall not fail to be treated as provided on the same terms within a specified class merely because the maximum dollar amount of payments and reimbursements which may be made under the terms of the arrangement for the year with respect to each employee within such class— (I) increases as additional dependents of the employee are covered under the arrangement, and (II) increases with respect to a participant as the age of the participant increases, but not in excess of an amount equal to 300 percent the lowest maximum dollar amount with respect to such a participant determined without regard to age. (D) Substantiation requirements An arrangement meets the requirements of this subparagraph if the arrangement has