2019 with respect to the 2018 crop year for county-level agriculture risk coverage payments under section 1117(b)(1) of the Agricultural Act of 2014 ( 7 U.S.C. 9017(b)(1) ), that provides all or some of the State Farm Service Agency offices in each State the opportunity to provide agricultural producers in the State a supplemental payment described in subsection (c) based on the alternate calculation method described in subsection (b) for 1 or more counties in a State if the office for that State determines that the alternate calculation method is necessary to ensure that, to the maximum extent practicable, there are not significant yield calculation disparities between comparable counties in the State. (b) The alternate calculation method referred to in subsection (a) is a method of calculating the actual yield for the 2018 crop year for county-level agriculture risk coverage payments under section 1117(b)(1) of the Agricultural Act of 2014 ( 7 U.S.C. 9017(b)(1) ), under which— (1) county data of the National Agricultural Statistics Service (referred to in this section as NASS data ) is used for the calculations