(a) Any person making contributions after July 1, 2007, that produce credits under § 2005 of this title, in amounts in excess of the maximum allowable credit permitted under § 2005 of this title shall be permitted to carry forward the excess contribution as a credit in any of the next 5 years subsequent to the date of the initial grant, subject to the limitation imposed by subsection (b) of this section.
(b) Excess contributions are those contributions that are not available as a credit in the year of the grant because of the limitation imposed by § 2005 of this title. The excess contributions carried over from prior years shall be allowable only after contributions for the current year have been credited, and in no event shall the total credit under this subchapter for any 1 year exceed the limitation imposed by § 2005 of this title.