201(g)(1) of the Social Security Act, from any one or all of the trust funds referred to in such section: Provided , That not less than $2,300,000 shall be for the Social Security Advisory Board: Provided further , That unobligated balances of funds provided under this paragraph at the end of fiscal year 2018 not needed for fiscal year 2018 shall remain available until expended to invest in the Social Security Administration information technology and telecommunications hardware and software infrastructure, including related equipment and non-payroll administrative expenses associated solely with this information technology and telecommunications infrastructure: Provided further , That the Commissioner of Social Security shall notify the Committees on Appropriations of the House of Representatives and the Senate prior to making unobligated balances available under the authority in the previous proviso: Provided further , That reimbursement to the trust funds under this heading for expenditures for official time for employees of the Social Security Administration pursuant to 5 U.S.C. 7131 , and for facilities or support services for labor organizations pursuant to policies, regulations, or procedures referred to in section 7135(b) of such title shall be made by the Secretary of the Treasury, with interest, from amounts in the general fund not otherwise appropriated, as soon as possible after such expenditures are made. Of the total amount made available under this heading, not more than $1,735,000,000, to remain available through March 31, 2019, is for the costs associated with continuing disability reviews under titles II and XVI of the Social Security Act, including work-related continuing disability reviews to determine whether earnings derived from services demonstrate an individual’s ability to engage in substantial gainful activity, for the cost associated with conducting redeterminations of eligibility under title XVI of the Social Security Act, for the cost of co-operative disability investigation units,