; or (II) 5 years after the last plan year for which the transition contribution rate applicable to the employer was established or updated. (ii) Exception The transition contribution rate applicable to an employer for the first plan year beginning on or after the commencement of the employer’s obligation to contribute to the composite plan is the rate in effect for the plan year of the legacy plan that commences on or after 180 days before such first plan year. (D) Effect of legacy plan financial circumstances If the plan actuary of the legacy plan has certified under section 305 that the plan is in endangered or critical status for a plan year, the transition contribution rate for the following plan year is the rate determined with respect to the employer under the legacy plan’s funding improvement or rehabilitation plan under section 305, if greater than the rate otherwise determined, but in no event greater than 75 percent of the sum of the contribution rates applicable to the legacy plan and the composite plan for the plan year. (E) Other actuarial assumptions and methods Except as provided in subparagraph (A), the determination of the transition contribution rate for a plan year shall be based on actuarial assumptions and methods consistent with the minimum funding determinations made under section 304 (or, if applicable, section 305) with respect to the legacy plan for the plan year. (F) Adjustments in rate The plan sponsor of a legacy plan from time to time may adjust the transition contribution rate or rates applicable to an employer under this paragraph by increasing some rates and decreasing others if the actuary certifies that such adjusted rates in combination will produce projected contribution income for the plan year beginning on or after the date of certification that is not less than would be produced by the transition contribution rates in effect at the time of the certification. (G) Notice of transition contribution rate The plan sponsor of a legacy plan shall provide notice to the parties to