improvement or rehabilitation plan under section 432, 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 431 (or, if applicable, section 432) 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 collective bargaining agreements pursuant to which contributions are made to the legacy plan of changes to the transition contribution rate requirements at least 30 days before the beginning of the plan year for which the rate is effective. (H) Notice to composite plan sponsor Not later than 30 days after a determination by the plan sponsor of a legacy plan that a collective bargaining agreement provides for a rate of contributions that is below the transition contribution rate applicable to one or more employers that are parties to the collective 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