Benefit Guaranty Corporation of the cessation of accruals, the period during which such cessation is in effect, and the reasons therefor. (4) Limitation on retroactive effect This subsection shall not apply to benefits accrued before the date on which notice is provided under paragraph (3). (d) Transition contribution requirements (1) In general A collective bargaining agreement satisfies the transition contribution requirements of this subsection if the agreement— (A) authorizes for payment of contributions to a legacy plan at a rate or rates equal to or greater than the transition contribution rate established under paragraph (2), and (B) does not provide for— (i) a suspension of contributions to the legacy plan with respect to any period of service, or (ii) any new direct or indirect exclusion of younger or newly hired employees of the employer from being taken into account in determining contributions owed to the legacy plan. (2) Transition contribution rate (A) In general The transition contribution rate for a plan year is the contribution rate that, as certified by the actuary of the legacy plan in accordance with the principles in section 432(b)(3)(B), is reasonably expected to be adequate— (i) to fund the normal cost for the plan year, (ii) to amortize the plan’s unfunded liabilities in level annual installments over 25 years, beginning with the plan year in which the transition contribution rate is first established, and (iii) to amortize any subsequent changes in the legacy plan’s unfunded liability due to experience gains or losses (including investment gains or losses, gains or losses due to contributions greater or less than the contributions made under the prior transition contribution rate, and other actuarial gains or losses), changes in actuarial assumptions, changes to the legacy plan’s benefits, or changes in funding method over a period of 15 plan years beginning with the plan year in which such change in unfunded liability is incurred. The transition contribution rate for any plan year may