; and (2) by adding at the end the following: (43) The term composite plan has the meaning given the term in section 801(a). . (b) Special funding rule for certain legacy plans (1) Amendment to Employee Retirement Income Security Act of 1974 Section 304(b) of the Employee Retirement Income Security Act of 1974 ( 29 U.S.C. 1084(b) ) is amended by adding at the end the following: (9) Special funding rule for certain legacy plans In the case of a multiemployer defined benefit plan that has adopted an amendment under section 801(b), in accordance with which no further benefits shall accrue under the multiemployer defined benefit plan, the plan sponsor may combine the outstanding balance of all charge and credit bases and amortize that combined base in level annual installments (until fully amortized) over a period of 25 plan years beginning with the plan year following the date all benefit accruals ceased. . (2) Amendment to Internal Revenue Code of 1986 Section 431(b) of the Internal Revenue Code of 1986 is amended by adding at the end the following: (9) Special funding rule for certain legacy plans In the case of a multiemployer defined benefit plan that has adopted an amendment under section 437(b), in accordance with which no further benefits shall accrue under the multiemployer defined benefit plan, the plan sponsor may combine the outstanding balance of all charge and credit bases and amortize that combined base in level annual installments (until fully amortized) over a period of 25 plan years beginning with the plan year following the date on which all benefit accruals ceased. . (c) Benefits after merger, consolidation, or transfer of assets (1) Amendment to Employee Retirement Income Security Act of 1974 Section 208 of the Employee Retirement Income Security Act of 1974 ( 29 U.S.C. 1058 ) is amended— (A) by striking so much of the first sentence as precedes may not merge and inserting the following: (1) In general Except as provided in paragraph (2), a pension plan may not merge, and