The Coast Guard polar icebreaker program is a program to acquire three new heavy polar icebreakers, to be followed years from now by the acquisition of up to three new medium polar icebreakers. The Coast Guard wants to begin construction of the first new heavy polar icebreaker in FY2019 and have it enter service in 2023. The polar icebreaker program has received about $359.6 million in acquisition funding through FY2018, including $300 million provided through the Navy's shipbuilding account and $59.6 million provided through the Coast Guard's acquisition account. The Coast Guard's proposed FY2019 budget requests $750 million in Coast Guard acquisition funding for the program. The acquisition cost of a new heavy polar icebreaker had earlier been estimated informally at roughly $1 billion, but the Coast Guard and Navy now believe that three heavy polar icebreakers could be acquired for a total cost of about $2.1 billion, or an average of about $700 million per ship. The first ship will cost more than the other two because it will incorporate design costs for the class and be at the start of the production learning curve for the class. When combined with the program's $359.6 million in prior-year funding, the $750 million requested for FY2019 would fully fund the procurement of the first new heavy polar icebreaker and partially fund the procurement of the second. The operational U.S. polar icebreaking fleet currently consists of one heavy polar icebreaker, Polar Star, and one medium polar icebreaker, Healy. In addition to Polar Star, the Coast Guard has a second heavy polar icebreaker, Polar Sea. Polar Sea, however, suffered an engine casualty in June 2010 and has been nonoperational since then. Polar Star and Polar Sea entered service in 1976 and 1978, respectively, and are now well beyond their originally intended 30-year service lives. The Coast Guard has used Polar Sea as a source of spare parts for keeping Polar Star operational. A Department of Homeland Security (DHS) Mission Need Statement (MNS) approved in June 2013 states that "current requirements and future projections ... indicate the Coast Guard will need to expand its icebreaking capacity, potentially requiring a fleet of up to six icebreakers (3 heavy and 3 medium) to adequately meet mission demands in the high latitudes...." The current condition of the U.S. polar icebreaker fleet, the DHS MNS, and concerns among some observers about whether the United States is adequately investing in capabilities to carry out its responsibilities and defend its interests in the Arctic, have focused policymaker attention on the question of whether and when to acquire one or more new heavy polar icebreakers as replacements for Polar Star and Polar Sea. On March 2, 2018, the U.S. Navy, in collaboration with the U.S. Coast Guard under the polar icebreaker integrated program office, released a request for proposal (RFP) for the advance procurement and detail design for the Coast Guard's heavy polar icebreaker, with options for detail design and construction for up to three heavy polar icebreakers. Issues for Congress for FY2019 for the polar icebreaker program include, inter alia, whether to approve, reject, or modify the Coast Guard's FY2019 acquisition funding request; whether to use a contract with options or a block buy contract to acquire the ships; whether to continue providing at least some of the acquisition funding for the polar icebreaker program through the Navy's shipbuilding account; and whether to procure heavy and medium polar icebreakers to a common basic design.