In general
The amount allowable as a credit under subsection (a) for any taxable year (determined without regard to subsection (c)) shall be reduced (but not below zero) by an amount which bears the same ratio to the amount so allowable (determined without regard to this paragraph but with regard to paragraph (1)) as—
(i)#
the amount (if any) by which the taxpayer’s adjusted gross income exceeds $150,000, bears to
(ii)#
$40,000.