Summary: The Swine Flu Program was the government's first attempt at immunization of the entire U.S. population and was based primarily on scientific judgments that a pandemic could occur at any time. No swine flu outbreak occurred during the 1976 and 1977 flu season. If recent experience shows that considerable money can be saved and if the Department of Health, Education, and Welfare (HEW) intends to continue rigorously testing and approving every vaccine lot, then total federal assumption of the liability coverage for vaccine production should be considered. Congress should establish a national liability policy before another immunization program is needed. HEW should continue its own potency tests on all lots of flu vaccine until manufacturers' test results can be relied on and should test vaccine intended for trial use as it would be tested for public use. The duration of protection provided by the vaccine is uncertain. In any future programs, state and local agencies will need better guidance and assistance from HEW in managing projects and will, in turn, have to make firm commitments to HEW. Expenditures for the Swine Flu Program reported by the Center for Disease Control were about $103 million. Total costs have not yet been accurately determined but may far exceed the $135 million appropriated.