building (and to eligible units within such building) under this subsection. Such dollar amount shall be allocated to months in the credit period with respect to such building (and such units) on the basis of the estimates described in paragraph (2)(B). (B) Allocation on project basis In the case of a project which includes (or will include) more than 1 building, the rental reduction credit amount shall be the dollar amount which is allocated to such project for all buildings included in such project. Subject to the limitation under subsection (e)(3)(B), such amount shall be allocated among such buildings in the manner specified by the taxpayer unless the qualified rental reduction agreement with respect to such project provides for such allocation. (2) State allocation (A) In general Except as provided in subparagraph (C), each rental reduction credit agency of a State shall each calendar year allocate its portion of the State rental reduction credit ceiling to qualified buildings (and to eligible units within each such building) in accordance with the State rental reduction allocation plan. (B) Allocations to each building The rental reduction credit amount allocated to any qualified building shall not exceed the aggregate qualified rental reduction amounts which such agency estimates will occur over the credit period for eligible units within such building, based on reasonable estimates of rents, family incomes, and vacancies in accordance with procedures established by the State as part of its State rental reduction allocation plan. (C) Specific allocations (i) Nonprofit organizations At least 25 percent of the State rental reduction credit ceiling for any State for any calendar year shall be allocated to qualified buildings in which a qualified nonprofit organization (as defined in section 42(h)(5)(C)) owns (directly or through 1 or more partnerships) an interest and materially participates (within the meaning of section 469(h)) in the operation of the building throughout the credit period. A State may