Limitation

(A) In general The amount determined under this paragraph is an amount equal to the product of— (i) 30 percent (adjusted as may be provided under subparagraph (B)) of the amount (computed on a daily basis) in effect under subsection (b)(2)(D) for the calendar year in which the taxable year of the individual begins, multiplied by (ii) the number of days of such taxable year within the applicable period described in subparagraph (A) or (B) of subsection (d)(1).

(B) Regulations The Secretary may issue regulations or other guidance providing for the adjustment of the percentage under subparagraph (A)(i) on the basis of geographic differences in housing costs relative to housing costs in the United States.