(3) High-need school (A) In general The term “high-need school” means— (i) an elementary school or middle school in which not less than 50 percent of the enrolled students are children from low-income families; or (ii) a high school in which not less than 40 percent of the enrolled students are children from low-income families, which may be calculated using comparable data from the schools that feed into the high school. (B) Low-income family For purposes of subparagraph (A), the term “low-income family” means a family— (i) in which the children are eligible for a free or reduced-price lunch under the Richard B. Russell National School Lunch Act ( 42 U.S.C. 1751 et seq.); (ii) receiving assistance under the program of block grants to States for temporary assistance for needy families established under part A of title IV of the Social Security Act ( 42 U.S.C. 601 et seq.); or (iii) in which the children are eligible to receive medical assistance under the Medicaid program under title XIX of the Social Security Act ( 42 U.S.C. 1396 et seq.).