This bill, titled the Plum Island Preservation Study Act, directs the Secretary of the Interior to undertake a comprehensive study of Plum Island in New York. The primary goal of this study is to evaluate the suitability of designating all or a portion of the island as a unit of the National Park System or the National Wildlife Refuge System , or to explore alternative means of protecting its valuable resources. The study area encompasses the entire consolidated Federal asset, including the Orient Point facility and all supporting infrastructure. In conducting the study, the Secretary is required to assess the island's national significance, consult with various federal agencies, state and local entities, and private organizations, and identify detailed cost estimates for any proposed federal acquisition, development, operation, and maintenance. Ultimately, a report outlining the study's findings, conclusions, and the Secretary's recommendations must be submitted to Congress within three years of funding availability.