SECTION 1. MODIFICATIONS AND INCREASED VOLUME CAP WITH RESPECT TO 
              QUALIFIED MORTGAGE BONDS.

    (a) Use of Qualified Mortgage Bonds Proceeds for Subprime 
Refinancing Loans.--Section 143(k) of the Internal Revenue Code of 1986 
(relating to other definitions and special rules) is amended by adding 
at the end the following new paragraph:
            ``(12) Special rules for subprime refinancings.--
                    ``(A) In general.--In the case of a residence which 
                was originally financed by the mortgagor through a 
                qualified subprime loan, this section shall be applied 
                with the following modifications:
                            ``(i) Subsection (i)(1) (relating to 
                        mortgages must be new mortgages) shall not 
                        apply.
                            ``(ii) Subsection (a)(2)(D)(i) shall be 
                        applied by substituting `12-month period' for 
                        `42-month period' each place it appears.
                            ``(iii) Subsection (d) (relating to 3-year 
                        requirement) shall not apply.
                            ``(iv) Subsection (e) (relating to purchase 
                        price requirement) shall be applied by using 
                        the market value of the residence at the time 
                        of refinancing in lieu of the acquisition cost.
                    ``(B) Qualified subprime loan.--
                            ``(i) In general.--The term `qualified 
                        subprime loan' means an adjustable rate single-
                        family residential mortgage loan originated 
                        after December 31, 2001, and before January 1, 
                        2008, that the bond issuer determines has 
                        characteristics that suggest both a reasonably 
                        foreseeable risk of default and a reasonable 
                        potential to avoid default with the benefit of 
                        a lower cost refinancing.
                            ``(ii) Considerations.--In making the 
                        determination under clause (i), the bond issuer 
                        may consider the following characteristics:
                                    ``(I) Loan payments which are 
                                scheduled to increase by more than 10 
                                percent after December 31, 2007, and 
                                before January 1, 2011.
                                    ``(II) A loan-to-value ratio of 97 
                                percent or greater at the time of the 
                                original mortgage loan or at the time 
                                of the refinancing of such loan after 
                                adjustment for any decline in the fair 
                                market value of the residence.
                                    ``(III) A borrower whose 
                                creditworthiness is relatively low in 
                                comparison to a prime borrower, based 
                                on a lower credit score, such as a Fair 
                                Isaac Credit Organization credit score 
                                at the time of the original subprime 
                                loan of less than 660 and the absence 
                                of an increase in such score by more 
                                than 10 percent since the time of the 
                                original loan.
                                    ``(IV) Whether loan payments on the 
                                original mortgage loan generally have 
                                been made in a current, timely manner, 
                                subject only to isolated late payments.
                    ``(C) Termination.--This paragraph shall not apply 
                to any bonds issued after December 31, 2010.''.
    (b) Increased Volume Cap for Qualified Mortgage Bonds.--
            (1) In general.--Subsection (d) of section 146 of the 
        Internal Revenue Code of 1986 is amended by adding at the end 
        the following new paragraph:
            ``(5) Increase and set aside for qualified mortgage bonds 
        for 2008.--
                    ``(A) In general.--The State ceiling for calendar 
                year 2008 shall be increased by $15,000,000,000.
                    ``(B) Set aside.--
                            ``(i) In general.--Not less than an amount 
                        equal to each State's allocable share of the 
                        increase in the State ceiling under 
                        subparagraph (A) shall be allocated solely for 
                        the purpose of a qualified mortgage issue which 
                        meets the requirement clause (ii).
                            ``(ii) Requirement.--A qualified mortgage 
                        issue meets the requirement of this clause if 
                        such issue meets the requirement of section 
                        143(a)(2)(D)(i) (determined by substituting 
                        `12-month period' for `42-month period' each 
                        place it appears).''.
            (2) Carryforward of unused limitations.--Subsection (f) of 
        section 146 of such Code is amended by adding at the end the 
        following new paragraph:
            ``(6) Special rules for increased volume cap under 
        subsection (d)(5).--No amount which is attributable to the 
        increase under subsection (d)(5) may be used--
                    ``(A) for a carryforward purpose other than issuing 
                qualified mortgage bonds, and
                    ``(B) to issue any bond after calendar year 
                2010.''.
    (c) Alternative Minimum Tax.--
            (1) In general.--Clause (ii) of section 57(a)(5)(C) of the 
        Internal Revenue Code of 1986 is amended by striking ``shall 
        not include'' and all that follows and inserting ``shall not 
        include--
                                    ``(I) any qualified 501(c)(3) bond 
                                (as defined in section 145), or
                                    ``(II) any qualified mortgage bond 
                                (as defined in section 143(a)) or 
                                qualified veterans' mortgage bond (as 
                                defined in section 143(b)) issued after 
                                December 31, 2007, and before January 
                                1, 2011.''.
            (2) Conforming amendment.--The heading for section 
        57(a)(5)(C)(ii) is amended by striking ``qualified 501(c)(3) 
        bonds'' and inserting ``certain bonds''.
    (d) Effective Date.--The amendments made by this section shall 
apply to bonds issued after December 31, 2007.
Output: Amends the Internal Revenue Code to: (1) allow proceeds of qualified mortgage bonds to be used to refinance certain residential subprime loans issued between 2002 and 2008; (2) increase in 2008 limitations on issuance amounts for qualified mortgage bonds; and (3) exempt tax-exempt interest on qualified mortgage or veterans' mortgage bonds issued before 2011 from the alternative minimum tax.