B roadly understood, domestic content restrictions are provisions which require that items purchased using specific funds appropriated by Congress be produced or manufactured in the United States. Over the years, Congress has enacted a number of such restrictions, pursuant to its broad power over federal spending, in order to protect U.S. businesses and labor by generally barring the use of federal funds to purchase "foreign" products. However, these restrictions are potentially less stringent than they might at first appear, since Congress has permitted the President to waive them so that the United States may comply with its obligations under various international trade agreements and accomplish certain other goals, or expressly provided for supplies produced or manufactured in countries with which the United States has trade agreements to be treated the same as supplies produced or manufactured domestically. Such promotion of trade has also been seen as generally benefitting U.S. firms and labor by facilitating the export of supplies and services in whose production the United States enjoys competitive advantages. Federal law currently has four major domestic content regimes, which apply in different contexts and impose different requirements upon the use of federal procurement, grant, and other funds: 1. The Buy American Act of 1933 , as amended, generally requires federal agencies to purchase "domestic end products" and use "domestic construction materials" on contracts exceeding the micro-purchase threshold (typically $3,500) performed in the United States. 2. The Trade Agreements Act of 1979 , as amended, permits the waiver of the Buy American Act and has resulted in "eligible products" from "designated countries" receiving equal consideration with domestic offers when certain federal agencies procure certain goods or services whose value exceeds certain monetary thresholds. 3. The Berry Amendment (10 U.S.C. §2533a) and its former "specialty metals" provision , now codified at 10 U.S.C. §2533b, require that food, clothing, tents, certain textile fabrics and fibers, and hand or measuring tools purchased by the Department of Defense (DOD) be entirely grown, reprocessed, reused, or produced in the United States; and that any "specialty metals" contained in any aircraft, missile and space system, ship, tank and automotive item, weapon system, ammunition, or any components thereof, purchased by DOD be melted or produced in the United States. 4. The Buy America Act —which is the popular name for a group of domestic content restrictions that have been attached to specific grant funds administered by the Department of Transportation (DOT) and certain other federal agencies—generally requires that steel, iron, and manufactured products made primarily of steel or iron and used in infrastructure projects be produced or manufactured in the United States. However, there are also a number of other domestic content restrictions that apply in specific contexts and, in many cases, are intended to address perceived "gaps" left by the four major domestic content regimes noted above. This report provides an overview of the Buy American Act, Trade Agreements Act, Berry Amendment (including its former specialty metals provision), and Buy America Act, specifically highlighting the commonalities and differences among them. The report also lists other federal domestic content restrictions codified in the U.S. Code . It does not address state or local "Buy American" provisions; nor does it address use of the "Made in America" label. It is also important to note that existing domestic content restrictions generally pertain to the place of production or manufacture of supplies. They generally do not address the place of performance of services, or, with certain exceptions, the nationality of the vendor. The Buy American Act is the earliest and arguably the best known of the major domestic content restrictions. On its face, the Buy American Act appears to prohibit federal agencies from acquiring "foreign" goods by providing that "[o]nly unmanufactured articles, materials, and supplies that have been mined or produced in the United States, and only manufactured articles, materials, and supplies that have been manufactured in the United States substantially all from articles, materials, or supplies mined, produced, or manufactured in the United States, shall be purchased for public use." As implemented, however, the act is better understood as generally establishing a price preference for domestic end products and construction materials. Specifically, the provisions of the Federal Acquisition Regulation (FAR) implementing the Buy American Act require that, when a domestic offer (i.e., an offer of a domestic end product) is not the low offer, the procuring agency must add a certain percentage of the low offer's price (inclusive of duty) to that offer before determining which offer is the lowest priced, or provides "best value" for the government. This percentage typically ranges from 6%, in cases where the lowest domestic offer is from a large business; to 12%, when the lowest domestic offer is from a small business; to 50%, for Department of Defense procurements, although agencies may adopt higher percentages by regulation. If the domestic offer is the lowest, or tied for lowest, after the application of this price preference, the agency must generally award the contract to the domestic offeror. However, if the foreign offer still has the lowest price, the agency may generally award the contract to the foreign offeror pursuant to provisions of the Buy American Act permitting the purchase of foreign end products, and the use of foreign construction materials, when the costs of domestic ones are "unreasonable." The Buy American Act makes separate provisions for federal agencies' purchase of supplies and their construction of "public works," as discussed below. It also incorporates several exceptions that permit the use of foreign end products and construction materials even if the cost of domestic ones is not "unreasonable." In addition, the application of the Buy American Act has been waived in certain procurements pursuant to the Trade Agreements Act (TAA). As implemented by the FAR, the Buy American Act generally requires that federal agencies acquiring supplies for use in the United States under a contract valued in excess of the micro-purchase threshold (typically $3,500) purchase "domestic end products." Whether an end product (i.e., an article, material, or supply to be acquired for public use) is "domestic" depends, in part, upon whether it is unmanufactured or manufactured. Unmanufactured end products must be mined or produced in the United States in order to qualify as "domestic" for purposes of the Buy American Act. Manufactured end products, in contrast, qualify as domestic if they are manufactured in the United States, and either (1) the cost of the components mined, produced, or manufactured in the United States exceeds 50% of the cost of all components, or (2) the end product is a commercially available off-the-shelf (COTS) item. The meaning of "manufacture" is not defined by the Buy American Act, executive orders implementing the act, or the FAR, and determining whether particular activities constitute "manufacturing"—such that a product can be said to be manufactured in the United States—can be complicated. In answering this question, judicial and other tribunals have, at various times, considered whether there were "substantial changes in physical character"; whether separate manufacturing stages were involved, or whether there was one continuous process; and whether the article is completed in the form required by the government. Operations performed after the item has been completed (e.g., packaging, testing) generally are not viewed as manufacturing. The cost of components, in turn, is generally determined based upon certain costs incurred by the contractor in purchasing or manufacturing the components. Specifically, for components purchased by the contractor, the cost of components includes the acquisition costs (including transportation costs to the place of incorporation into the end product), and any applicable duty (regardless of whether a duty-free certificate of entry is issued); and for components manufactured by the contractor, the cost of components includes all costs associated with the manufacture of the component (including transportation costs), and allocable overhead costs, but excludes profits and any costs associated with the manufacture of the end product. Specific components generally need not be manufactured in the United States, so long as at least 50% of the costs of all components are mined, produced, or manufactured in the United States, or the end product is a COTS item. In general, anything that is not itself acquired as an end product is seen as a component, even if the agency could theoretically have purchased it as an end product. The Buy American Act also generally requires that domestic materials be used in federal agencies' construction projects by prohibiting them from "allow[ing] the contractor to acquire foreign construction materials." Construction material generally includes any "article, material, or supply brought to the construction site by a contractor or subcontractor for incorporation into [a] building or work," including items brought to the site preassembled from articles, materials, or supplies. However, materials purchased directly by the government are treated as supplies, not construction materials. Domestic construction material includes unmanufactured construction material mined or produced in the United States, as well as construction material manufactured in the United States, provided that (1) the cost of the components mined, produced, or manufactured in the United States exceeds 50% of the cost of all components, or (2) the material is a COTS item. Manufacture is determined in the same way as for end products, and the costs of construction materials are also generally calculated in the same way as the costs of end products. The FAR lists five "exceptions" to the Buy American Act, or five circumstances in which an agency may purchase foreign end products, or permit the use of foreign construction materials, without violating the act.