; of which not less than $10,000,000 shall be available for facilities repair and maintenance projects. Transportation security administration Operations and support For necessary expenses of the Transportation Security Administration for operations and support, $7,302,455,000, to remain available until September 30, 2020: Provided , That not to exceed $7,650 shall be for official reception and representation expenses: Provided further , That security service fees authorized under section 44940 of title 49, United States Code, shall be credited to this appropriation as offsetting collections and shall be available only for aviation security: Provided further , That the sum appropriated under this heading from the general fund shall be reduced on a dollar-for-dollar basis as such offsetting collections are received during fiscal year 2019 so as to result in a final fiscal year appropriation from the general fund estimated at not more than $4,632,455,000. Procurement, construction, and improvements For necessary expenses of the Transportation Security Administration for procurement, construction, and improvements, $189,629,000, to remain available until September 30, 2021. Research and development For necessary expenses of the Transportation Security Administration for research and development, $20,594,000, to remain available until September 30, 2020. Coast Guard Operations and support For necessary expenses for the operations and support of the Coast Guard, not otherwise provided for; purchase or lease of not to exceed 25 passenger motor vehicles, which shall be for replacement only; purchase or lease of small boats for contingent and emergent requirements (at a unit cost of not more than $700,000) and repairs and service-life replacements, not to exceed a total of $31,000,000; purchase or lease of boats necessary for overseas deployments and activities; payments pursuant to section 156 of Public Law 97–377 ( 42 U.S.C. 402 note; 96 Stat. 1920); and recreation and welfare; $7,792,409,000