As a signatory member of the World Trade Organization (WTO), the United States has committed to abide by WTO rules and disciplines, including those that govern domestic farm policy. The WTO's general rules concerning subsidy disciplines, trade behavior, and market access concessions apply to all members. In addition, each individual member country also negotiated its own specific policy commitments—spelled out in a document called a Schedule of Concessions (or Country Schedule). Trade plays a critical role in the U.S. agricultural sector. USDA estimates that exports account for about 20% of total U.S. agricultural production. Because the United States plays such an important role in so many agricultural markets, its farm policy is often subject to intense scrutiny, both for compliance with current WTO rules and for its potential to diminish the breadth or impede the success of future multilateral negotiations—in part because a farm bill locks in U.S. policy behavior for an extended period of time, during which the United States would be unable to accept any new restrictions on its domestic support programs. Current U.S. farm policy is authorized by the 2014 farm bill (the Agricultural Act of 2014; P.L. 113-79 ) for the 2014-2018 crop years. The 2014 farm bill made significant changes to U.S. farm price and income support programs. These changes could have important implications for U.S. commitments to the WTO in terms of compliance with current spending limits and with rules on mitigating program spillover effects and distortions in international markets. This report assumes knowledge of the U.S. farm safety net programs and their function. It briefly describes the relevant WTO rules governing domestic support programs under the Agreement on Agriculture (AoA) and the Agreement on Subsidies and Countervailing Measures (SCM). The report then reviews the current U.S. farm safety net programs, including changes made under the 2014 farm bill, particularly to Title I price and income support programs, in light of their potential for compliance with the AoA and SCM and their potential to affect the success of the current Doha Round of multilateral trade negotiations. Table 1 provides a list of current farm safety net programs. Table 2 lists key parameters of the farm support programs referenced in this report. Table 3 , at the end of the report, briefly reviews each of the individual 2014 farm bill provisions that are relevant to WTO commitments, including a description of their function, average outlays, any changes made under the 2014 farm bill, WTO status, and related potential WTO effects. A domestic farm support program can violate WTO commitments in two principal ways—first, by exceeding amber box spending limits (see box below), and second, by generating market distortions that spill over into the international marketplace and cause significant or measurable adverse effects. For such a violation to be meaningful, another WTO member country must successfully challenge the violation under the WTO dispute settlement process. The Agreement on Agriculture (AoA) spells out the rules for countries to determine whether their policies for any given year are potentially trade-distorting, calculate the costs of any distortion, and report those costs to the WTO in a public and transparent manner. The United States is committed, under the AoA, to spend no more than $19.1 billion annually on amber box programs, subject to DM exemptions. Since 1995, when the AoA rules first came into effect and member countries began notifying their outlays on domestic support, the United States has stayed within its amber box limits ( Figure 1 ). However, U.S. compliance has hinged on judicious use of the DM exemptions in a number of years (e.g., 1999-2001 and 2005). This has included the notification of crop insurance premium subsidies during the 1995 to 2011 period as non-product-specific support (see the red bars for 1995-2011 in Figure 1 ), which then allowed for these outlays to be exempted under the DM exclusion for non-product-specific spending, as described later in this report. In its most recent notification (2012), the United States changed its notification status for crop insurance premium subsidies to product-specific support. A total of $11.8 billion in amber box outlays were notified as "product-specific" in 2012, including $7.0 billion of crop insurance subsidies. However, $5.0-billion product-specific amber box outlays were excluded under the DM product-specific exemption (see the yellow bar for 2012 in Figure 1 ), thus reducing U.S. amber box outlays subject to a spending limit to $6.864 billion. In addition to potentially exceeding payment limits, a market-distorting program may be challenged under Articles 5(c) and 6.3 of the Agreement on Subsidies and Countervailing Measures (SCM) when the program's effect spills over into international markets—that is, if it can be established that a subsidy causes adverse market effects. The importance of SCM rules has been made salient by the so-called "Brazil cotton case," in which a WTO dispute settlement panel ruled against both the U.S. cotton price and income support programs and the GSM-102 export credit guarantee program. As a result of the ruling and the potential for WTO-sanctioned retaliation, the United States made substantial policy changes in the past two farm bills to bring the related programs into WTO compliance. Because the United States is a major producer, consumer, exporter, and/or importer of many agricultural commodities, the SCM is relevant for most major U.S. agricultural products. If a particular U.S. farm program is deemed to result in a market distortion that adversely affects other WTO members—even if it is within agreed-upon AoA spending limits—then that program may be subject to challenge under the WTO dispute settlement procedures (see box below). For any farm program that is challenged under the SCM, a WTO dispute settlement panel reviews the relevant trade and market data and makes a determination of whether the program resulted in a significant market distortion . Following these guidelines, a subsidy may be found to be actionable or prohibited. WTO actionable subsidies (i.e., policies that incentivize overproduction and result in lower market prices or altered trade patterns) must be withdrawn or altered to minimize or eliminate the subsidy's distorting aspect. WTO prohibited subsidies (i.e., certain export- and import-substitution subsidies not included in a member's country schedule) must be stopped or withdrawn "without delay," in accordance with an abbreviated timetable announced by the WTO ruling panel. If the violating policies are not withdrawn or altered according to the timetable, then the WTO member bringing the challenge may take appropriate countermeasures. Perhaps the most easily recognized distortion occurs when a program offers price support or income payments based on (i.e., coupled to) the current level of farm activity—either area planted or volume of output. Such an incentive can encourage greater production or output than the market is prepared to absorb and, as a result, tends to lower market prices. Given the United States' prominent role in international agricultural markets, such potential market distortions, should they emerge, can be quickly transmitted from domestic to global markets. Since most governing provisions for U.S. farm programs are statutory, new legislation may be required to implement even minor changes to achieve compliance in the event that a WTO challenge successfully finds a program in violation of a WTO rule. So, a key question that policymakers ask of virtually every existing farm program, as well as of new farm proposals, is how it will affect U.S. commitments under the AoA and U.S. compliance with SCM rules. The answer rests not only on cost, but also on each program's design, implementation, and subsequent market effects. The Agricultural Act of 2014 reshaped the structure of U.S. commodity support, otherwise known as the farm "safety net." In general, the new suite of farm support programs shifts support away from the green/amber boxes and toward the blue/amber boxes, thus indicating greater potential for market distortion. In particular, the 2014 farm bill: terminated several of the core "farm safety net" programs from the previous 2008 farm bill, including direct payments (DP), the counter-cyclical payment (CCP) program, and the Average Crop Revenue Election (ACRE) and Supplemental Revenue Assurance (SURE) programs; retained the traditional marketing loan program (MLP)—which triggers payments when market prices drop below support levels (referred to as loan rates)—but with a single adjustment to the loan rate for upland cotton (which is now allowed to float within a formula-determined range of 45¢/lb to 52¢/lb as compared with the previous fixed value of 52¢/lb); replaced CCP with a similar counter-cyclical payment program called Price Loss Coverage (PLC) using substantially higher reference support prices; added several new shallow-loss programs, including Agricultural Risk Coverage (to replace ACRE) with county-level (ARC-CO) and farm-level (ARC-ID) options, a Supplemental Coverage Option (SCO), and Stacked Income Protection (STAX); and repealed the previous dairy product price support (DPPS) and Milk Income Loss Contract (MILC) programs and replaced them with a new Dairy Margin Protection Program (DMPP) and Dairy Product Donation Program (DPDP). Evaluating the merits of a domestic support program depends on one's perspective. This is because costs to the federal budget usually do not equal costs (or distortions) in the international marketplace.