Congress over the years has passed several domestic content laws that aim to protect American manufacturing and manufacturing jobs. In 1978, Congress placed domestic content restrictions on federally funded transportation projects that are carried out by nonfederal government agencies such as state and local governments. These restrictions are commonly referred to as the Buy America Act, or more simply, Buy America; they differ from requirements under the Buy American Act of 1933, which applies to direct purchases by the federal government. Statements and actions by the Trump Administration about reinvigorating domestic manufacturing and reinvesting in infrastructure have stimulated renewed interest in Buy America. Today, Buy America refers to several similar statutes and regulations that apply to federal funds used to support projects in highways, public transportation, aviation, and intercity passenger rail, including Amtrak. Buy America also applies to certain federally funded water infrastructure projects. Unless a nationwide or project-specific waiver is granted, Buy America requires the use of U.S.-made iron and steel and the domestic production and assembly of other manufactured goods, such as rolling stock used in public transportation. To evaluate the implications of Buy America on domestic manufacturing, this report analyzes the effects of Buy America on steel and rolling stock manufacturing in the context of industry trends. It also briefly discusses the effects of Buy America on the transportation system. The report begins by explaining Buy America restrictions in more detail; how Buy America comports with international trade agreements that generally forbid procurement restrictions favoring domestic products; and how a relatively new provision enacted by Congress may require imports of materials on federally funded transportation projects to be carried on U.S.-flag ships . The report identifies policy options Congress might consider in light of recent legislative proposals. Buy America requirements differ in law and regulation according to the specific funding program and administering agency (see Table A-1 ). These agencies are the Federal Transit Administration (FTA), the Federal Highway Administration (FHWA), the Federal Railroad Administration (FRA), and the Federal Aviation Administration (FAA). Buy America also applies to purchases by Amtrak. In certain situations, the statutes permit a regulating agency to waive the Buy America provisions. If a state or local government does not use federal funds on a project, the project is not subject to Buy America (although states may have laws imposing similar requirements on state-funded purchases). Buy America provisions applicable to funds administered by FHWA, for example, are found at 23 U.S.C. §313 and 23 C.F.R. §635.410, and apply to iron and steel permanently incorporated into a highway project. This requirement can be waived if the Secretary of Transportation determines that it would be inconsistent with the public interest, that the materials are not produced in the United States in sufficient quantities or of a satisfactory quality, or that the inclusion of domestic materials will raise the cost of the overall project by more than 25%. FHWA determined in a 1983 rulemaking that Buy America would not apply to raw materials, such as iron ore, limestone, and waste products, all of which "may be imported." Waste products that may be used under this waiver include scrap steel. FHWA also waived the application of Buy America requirements to products other than those manufactured predominantly of iron and steel. In 2012, FHWA clarified that a manufactured product must consist of at least 90% iron and steel for it to be considered manufactured predominantly of iron and steel and, thus, subject to Buy America requirements. In 1995, FHWA determined that due to inadequate national supply, a national waiver would be granted for certain iron products used in the manufacture of steel or iron, including pig iron and iron ore that is reduced, processed, or pelletized. Even though FHWA waives Buy America requirements for manufactured products, except those made predominantly of iron and steel, this is not the case with other U.S. Department of Transportation (DOT) agencies and Amtrak. For example, for the purchase of rolling stock using FTA funds, the Buy America requirement is waived only if (1) the cost of the components produced in the United States in FY2017 is more than 60% of the cost of all components of the rolling stock (65% for FY2018 and FY2019, and 70% for FY2020 onward); and (2) final assembly of the rolling stock occurs in the United States (49 U.S.C. §5323(j) and 49 C.F.R. §661). Moreover, for a rolling stock component to be considered produced in the United States or of domestic origin, "more than 60% of the subcomponents of that component, by cost, must be of domestic origin, and the manufacture of the component must take place in the United States" (49 C.F.R. §661.11(g)). For nonrolling stock manufactured goods purchased using FTA funds , 100% of the components, including steel and iron, mu st be made in the United States and assembly must be done in the United States . According to 49 C.F.R. §661.5, "a component is considered of U.S. origin if it is manufactured in the United States, regardless of the origin of its subcomponents." Buy America provisions restrict Amtrak's spending when the cost of articles, materials, or supplies bought is at least $1 million. The law requires Amtrak to purchase goods that are manufactured in the United States "substantially from articles, material, and supplies mined, produced, or manufactured in the United States." FRA has interpreted "substantially" to mean that the manufactured goods must have domestic component content greater than 50%, by cost. The U.S. government builds few transportation projects directly. Instead, it generally funds highways, airports, and public transportation projects by making grants or loans to state or local governments. This funding structure has made it possible to avoid claims that Buy America violates international trade agreements. The United States is a signatory to international agreements that restrict discrimination against trading partners in government procurement. Currently, 47 World Trade Organization (WTO) members, including the United States, have made binding commitments under the WTO Agreement on Government Procurement (GPA), whereby each provides the others access to its national procurement markets. Most U.S. bilateral and regional free trade agreements also include public procurement provisions. These agreements are generally based on "national treatment" and require the United States to treat goods, services, and suppliers of other signatories no less favorably than U.S. goods, services, and suppliers. As a consequence, firms based in countries covered by such agreements can bid on covered U.S. government procurement contracts over a certain dollar threshold. The thresholds are adjusted every two years. National treatment also means U.S. firms can bid on contracts in foreign procurement markets, giving American suppliers treatment no less favorable than domestic suppliers. Although the United States is a WTO GPA signatory, state and local governments are excluded from coverage, even if federal funds are involved, unless they voluntarily agree to comply. Thus, where the federal government provides grants or loans to state and local authorities for transportation projects, it may attach domestic sourcing restrictions to these funds without violating international obligations. The exclusion of subnational procurement has caused considerable tension with major U.S. trading partners such as Canada and the European Union. In 2010, for example, the United States agreed to allow Canadian firms to bid on certain subnational economic stimulus contracts, including those involving construction of highways, bridges, and rail lines, in return for Canada's agreement to cover its provinces and territories under the WTO GPA. Cargo preference is another restriction applicable to federally supported activities, in this case requiring that a portion of "government-impelled" cargoes be carried on U.S.-flag vessels (46 U.S.C. §55305, 46 C.F.R. Part 381). Although cargo preference is not a Buy America requirement, a relatively new cargo preference provision may complicate transportation projects that are subject to Buy America. In 2008, Congress incorporated a provision in the FY2009 Duncan Hunter National Defense Authorization Act (NDAA; P.L. 110-417 , §3511) specifying that cargo preference requirements also apply to cargo that is imported by an organization or person if the federal government "provides financing in any way with federal financial funds for the account of any persons unless otherwise exempted." At least 50% of such cargo must be shipped in U.S.-flag vessels. The law directs DOT to issue regulations and guidance to govern the administration of cargo preference by other federal agencies. The Maritime Administration (MARAD) within DOT has yet to clarify how the cargo preference requirements of the FY2009 NDAA will be implemented. The agency submitted a draft notice of proposed rulemaking for Office of Management and Budget approval in December 2011, but subsequently terminated the process after interagency coordination efforts failed. MARAD anticipates restarting the regulatory development process, but does not know when. FHWA has interpreted the law to apply cargo preference requirements to federally supported highway projects carried out by state departments of transportation and other agencies. MARAD has applied cargo preference requirements to vessel components imported for ships constructed with federal loan guarantees. There have been several changes to Buy America in the two most recent surface transportation reauthorization acts, the Moving Ahead for Progress in the 21 st Century Act (MAP-21; P.L. 112- 141 ), enacted in July 2012, and the Fixing America's Surface Transportation (FAST) Act ( P.L. 114-94 ), enacted in December 2015. As part of MAP-21, Congress sought to prevent sponsors of highway projects from segmenting a project into smaller parts, some federally funded and some not, so as to free some segments of the project from Buy America requirements.