basis as such offsetting collections are received during fiscal year 2018 so as to result in a final fiscal year appropriation from the general fund estimated at not more than $4,612,874,000. Procurement, construction, and improvements For necessary expenses of the Transportation Security Administration for procurement, construction, and improvements, $53,314,000, to remain available until September 30, 2020. Research and development For necessary expenses of the Transportation Security Administration for research and development, $20,190,000, to remain available until September 30, 2019. Coast guard Operating expenses For necessary expenses for the operations and maintenance of the Coast Guard, not otherwise provided for