bargaining agreement, the plan sponsor of the legacy plan shall notify the plan sponsor of any composite plan under which employees of such employer would otherwise be eligible to accrue a benefit. (3) Correction procedures Pursuant to standards prescribed by the Secretary of Labor, the plan sponsor of a composite plan shall adopt rules and procedures that give the parties to the collective bargaining agreement notice of the failure of such agreement to satisfy the transition contribution requirements of this subsection, and a reasonable opportunity to correct such failure, not to exceed 180 days from the date of notice given under subsection (b)(2). (4) Supplemental contributions A collective bargaining agreement may provide for supplemental contributions to the legacy plan for a plan year in excess of the transition contribution rate determined under paragraph (2), regardless of whether the legacy plan is in endangered or critical status for such plan year. (e) Nonapplication of composite plan restrictions (1) In general The provisions of subsections (a), (b), and (c) shall not apply with respect to a collective bargaining agreement, to the extent the agreement, or a predecessor agreement, provides or provided for contributions to a defined benefit plan that is a legacy plan, as of the first day of the first plan year following a plan year for which the plan actuary certifies that the plan is fully funded, has been fully funded for at least three out of the immediately preceding 5 plan years, and is projected to remain fully funded for at least the following 4 plan years. (2) Determination of fully funded A plan is fully funded for purposes of paragraph (1) if, as of the valuation date of the plan for a plan year, the value of the plan’s assets equals or exceeds the present value of the plan’s liabilities, determined in accordance with the rules prescribed by the Pension Benefit Guaranty Corporation under sections 4219(c)(1)(D) and 4281 of Employee Retirement Income and Security Act for multiemployer plans