; (II) increase the limitation under this title on the amount of the maximum principal obligation of a mortgage that may be insured; or (III) decrease the amount required to be paid, in cash or its equivalent, on account of a property subject to a mortgage insured under this title. (v) Termination The authority to insure mortgages pursuant to this subparagraph on properties located in a county or counties shall terminate upon the earlier of— (I) the expiration of the 18-month period beginning upon the date that notification under clause (iii) is provided to the Congress of the determination under clause (i) with respect to such county or counties; or (II) the occurrence of the conditions identified pursuant to clause (ii) with respect to such county or counties. (vi) Multiple determinations Nothing in this subparagraph may be construed to prevent multiple or consecutive periods for a county or counties during which mortgages on properties located in such county or counties may be insured pursuant to this subparagraph. (D) Disaster area The Board of Directors exercises the authority to insure mortgages under this subparagraph, subject to the following requirements: (i) Implementation The Board of Directors may implement authority to insure mortgages under this subparagraph only if the Board— (I) by a vote of the majority of its members, approves such implementation for a specific disaster area under clause (iii) and a specific disaster period under clause (iv)