; $12,100,000 shall be derived from animal generic drug user fees authorized by 21 U.S.C. 379j–21 , and shall be credited to this account and remain available until expended; $672,000,000 shall be derived from tobacco product user fees authorized by 21 U.S.C. 387s , and shall be credited to this account and remain available until expended: Provided further , That in addition to and notwithstanding any other provision under this heading, amounts collected for prescription drug user fees, medical device user fees, human generic drug user fees, biosimilar biological product user fees, animal drug user fees, and animal generic drug user fees that exceed the respective fiscal year 2018 limitations are appropriated and shall be credited to this account and remain available until expended: Provided further , That fees derived from prescription drug, medical device, human generic drug, biosimilar biological product, animal drug, and animal generic drug assessments for fiscal year 2018, including any such fees collected prior to fiscal year 2018 but credited for fiscal year 2018, shall be subject to the fiscal year 2018 limitations: Provided further , That the Secretary may accept payment during fiscal year 2018 of user fees specified under this heading and authorized for fiscal year 2019, prior to the due date for such fees, and that amounts of such fees assessed for fiscal year 2019 for which the Secretary accepts payment in fiscal year 2018 shall not be included in amounts under this heading: Provided further , That none of these funds shall be used to develop, establish, or operate any program of user fees authorized by 31 U.S.C. 9701: Provided further , That of the total amount appropriated: (1) $1,026,003,000 shall be for the Center for Food Safety and Applied Nutrition and related field activities in the Office of Regulatory Affairs; (2) $1,634,678,000 shall be for the Center for Drug Evaluation and Research and related field activities in the Office of Regulatory Affairs