or reimbursed to the plan, plan participants, or plan beneficiaries, including payments and reimbursements made pursuant to subparagraph (A) if such amount is greater than the amount determined under subparagraph (A). . (B) Amount involved for purposes of excise tax The first sentence of section 4975(f)(4) of such Code is amended by striking excess compensation. and inserting excess compensation, and in the case of a prohibited transaction arising by the failure of investment advice to be a best interest recommendation, the amount involved shall be the amount paid to the person providing the advice (or its affiliate, as defined in paragraph (8)(J)(ii)) that has not been paid or reimbursed to the plan, plan participants, or plan beneficiaries, including payments and reimbursements made pursuant to paragraph (5). . (c) Effective date The amendments made by subsections (a) and (b) shall take effect on the date of the enactment of this Act and shall apply with respect to communications provided or recommendations made on or after 2 years after such date. (d) Grandfathered transactions and services The amendments made by subsections (a) and (b) shall not apply to any service or transaction rendered, entered into, or for which a person has been compensated prior to the date on which the amendments become effective under subsection (c). (e) Transition Until such time as regulations or other guidance are issued to carry out the amendments made by subsections (a) and (b), a plan or a fiduciary shall be treated as meeting the requirements of such amendments if the plan or fiduciary, as the case may be, complies with a reasonable good faith interpretation of such amendments.