agency, and (II) an Indian tribe, as defined in section 4(13) of the Native American Housing Assistance and Self-Determination Act of 1996 ( 25 U.S.C. 4103(13) ), including any tribally designated housing entity (as defined in section 4(22) of such Act ( 25 U.S.C. 4103(22) )), tribal subsidiary, subdivision, or other wholly owned tribal entity, (iv) a local, State, regional, or national coalition (with one lead organization which meets the eligibility requirements of clause (i), (ii), or (iii) acting as the applicant organization), or (v) in the case of a targeted population or community with respect to which no organizations described in the preceding clauses are available— (I) a State government agency, or (II) an office providing Cooperative Extension services (as established at the land-grant colleges and universities under the Smith-Lever Act of May 8, 1914). (3) Low-income taxpayers The term low-income taxpayer means a taxpayer whose income for the taxable year does not exceed an amount equal to the completed phaseout amount under section 32(b) for a married couple filing a joint return with 3 or more qualifying children, as determined in a revenue procedure or other published guidance. (4) Underserved population The term underserved population includes populations of persons with disabilities, persons with limited English proficiency, Native Americans, individuals living in rural areas, members of the Armed Forces and their spouses, and the elderly. (f) Special rules and limitations (1) Duration of grants Upon application of a qualified return preparation program, the Secretary is authorized to award a multi-year grant not to exceed 3 years. (2) Aggregate limitation Unless otherwise provided by specific appropriation, the Secretary shall not allocate more than $30,000,000 per fiscal year (exclusive of costs of administering the program) to grants under this section. (g) Promotion and referral (1) Promotion The Secretary shall promote tax preparation through qualified return preparation programs through