; and (B) variations in costs on a county-by-county basis for medical assistance and administrative expenses. (2) Method of adjustment (A) In general The adjustments under paragraph (1) shall be made in a manner similar to the manner in which similar adjustments are made under subsection (c)(2)(C) and consistent with the requirements of clause (iii) of such subsection and subparagraph (B). (B) Biannual update of risk adjustment methodology In applying clause (i)(I) of subsection (c)(2)(C) for purposes of subparagraph (A), the Secretary shall, in consultation with the entities described in clause (ii)(I) of such subsection, update the risk adjustment methodology applied as appropriate not less often than every 2 years. (f) Chronic care quality bonus payments (1) Determination of bonus payments If the Secretary determines that, based on the reports under paragraph (5) , with respect to categories of chronic disease for which chronic care performance targets had been established under paragraph (3) for each category of Medicaid beneficiaries specified under subsection (b)(2) such targets have been met by a State for a reform year, the Secretary shall make an additional payment to such State in the amount specified in paragraph (6) for each quarter in the succeeding reform year. Such payments shall be made in a manner specified by the Secretary and may only be used consistent with subsection (a)(3) . (2) Identification of categories of chronic disease The Secretary shall determine the categories of chronic disease for which bonus payments may be available under this subsection for each category of Medicaid beneficiaries. (3) Adoption of quality measurement system and identification of performance targets (A) System and data With respect to the categories of chronic disease under paragraph (2) , the Secretary shall adopt a quality measurement system that uses data described in paragraph (4) and is similar to the Five-Star Quality Rating System used to indicate the performance of Medicare Advantage plans under part C