422.12B  Earned income tax credit.
  1.  The taxes imposed under this division less the credits allowed under section 422.12 shall be reduced by an earned income credit equal to seven percent of the federal earned income credit provided in section 32 of the Internal Revenue Code. Any credit in excess of the tax liability is refundable.
  2.  Married taxpayers electing to file separate returns or filing separately on a combined return may avail themselves of the earned income credit by allocating the earned income credit to each spouse in the proportion that each spouse’s respective earned income bears to the total combined earned income. Taxpayers affected by the allocation provisions of section 422.8 shall be permitted a deduction for the credit only in the amount fairly and equitably allocable to Iowa under rules prescribed by the director.
89 Acts, ch 268, §6; 90 Acts, ch 1171, §4; 91 Acts, ch 159, §14; 91 Acts, ch 215, §3; 2000 Acts, ch 1146, §5, 9, 11; 2007 Acts, ch 161, §1, 22