shall be filed with the applicable authority not later than 90 days after the close of the plan year (or on such later date as may be prescribed by the applicable authority). The applicable authority may require by regulation such interim reports as it considers appropriate. (f) Engagement of Qualified Actuary The board of trustees of each association health plan which provides benefits options in addition to health insurance coverage and which is applying for certification under this part or is certified under this part shall engage, on behalf of all participants and beneficiaries, a qualified actuary who shall be responsible for the preparation of the materials comprising information necessary to be submitted by a qualified actuary under this part. The qualified actuary shall utilize such assumptions and techniques as are necessary to enable such actuary to form an opinion as to whether the contents of the matters reported under this part— (1) are in the aggregate reasonably related to the experience of the plan and to reasonable expectations, and (2) represent such actuary’s best estimate of anticipated experience under the plan. The opinion by the qualified actuary shall be made with respect to, and shall be made a part of, the annual report. 808. Notice requirements for voluntary termination Except as provided in section 809(b), an association health plan which is or has been certified under this part may terminate (upon or at any time after cessation of accruals in benefit liabilities) only if the board of trustees, not less than 60 days before the proposed termination date— (1) provides to the participants and beneficiaries a written notice of intent to terminate stating that such termination is intended and the proposed termination date, (2) develops a plan for winding up the affairs of the plan in connection with such termination in a manner which will result in timely payment of all benefits for which the plan is obligated, and (3) submits such plan in writing to the applicable authority. Actions