of applying subsection (b). . (b) Effective date The amendment made by this section shall apply to sales and exchanges after December 31, 2020. 602. Phase down of mortgage interest deduction (a) In general Section 163(h)(3) of the Internal Revenue Code of 1986 is amended by adding at the end the following new subparagraph: (G) Phasedown of deduction (i) In general In the case of amounts paid or accrued during a taxable year beginning after December 31, 2020, the amount of qualified residence interest allowed as a deduction under this section for such taxable year shall not exceed an amount equal to the applicable percentage of the qualified residence interest which would have been allowed as a deduction to the taxpayer under this section without regard to this subparagraph. (ii) Applicable percentage For purposes of clause (i), the applicable percentage shall be determined under the following table: In the case of taxable years The applicable beginning with or during: percentage shall be: 2021 90% 2022 80% 2023 70% 2024 60% 2025 50% 2026 40% 2027 30% 2028 20% 2029 10% 2030 and thereafter 0% . (b) Effective date The amendments made by this section shall apply to amounts paid or accrued during taxable years beginning after December 31, 2020. VII Supported alternatives to penalization of persons experiencing homelessness 701. Grant authorization The Attorney General is authorized to make grants to States, units of local government, public and community defender systems, and nonprofit organizations to create or expand alternatives to penalizing homelessness (as such term is defined in section 3 of this Act). 702. Application (a) In general An entity seeking a grant under this title shall submit to the Attorney General an application at such time, in such manner, and containing such information as the Attorney General may reasonably require, including an assurance described in subsection (b). (b) Assurance described An assurance described in this subsection is an assurance that the entity has in place a policy