; and (ii) the date on which the period of limitation for instituting an action against the Administrator on the claim under section 1333 or 1341, as applicable, will end. (e) Optional arbitration Not later than 180 days after the date of enactment of this subsection, the Administrator shall by regulation establish a process through which a flood insurance policyholder, instead of submitting an appeal under subsection (d) to the Administrator, may request that the appeal be heard through independent, binding arbitration. . (b) Relation to regulations and other law Nothing in the amendment made by subsection (a) shall be construed to require the Administrator to repeal the regulations promulgated under section 205 of the Bunning-Bereuter-Blumenauer Flood Insurance Reform Act of 2004 ( 42 U.S.C. 4011 note), or to promulgate new regulations, except as necessary to implement that amendment. 405. Accountability for underpayments by Write Your Own companies Section 1348 of the National Flood Insurance Act of 1968 ( 42 U.S.C. 4084 ) is amended by adding at the end the following: (c) Accountability for underpayments The Administrator shall require that, if the Administrator determines through an audit that the pool or an insurance company or other private organization described in subsection (a) has underpaid a claim of a policyholder— (1) the pool, insurance company, or other private organization, as applicable, shall pay the amount of the difference to the Administrator