The Supplemental Nutrition Assistance Program (SNAP) is the nation's largest domestic food assistance program, serving about 42.2 million recipients in an average month at a federal cost of over $68 billion in FY2017. SNAP is jointly administered by the state agencies, which handle most recipient functions, and the federal government--specifically, the U.S. Department of Agriculture's Food and Nutrition Service (USDA-FNS)--which supports and oversees the states and handles most retailer functions. In a program with so many diverse stakeholders, detecting, preventing, and addressing errors and fraud is complex. SNAP has typically been reauthorized in a farm bill approximately every five years; this occurred most recently in 2014 (P.L. 113-79). Policymakers have long been interested in reducing fraud and improving payment accuracy in the program. Provisions related to these goals have been included in past farm bill reauthorizations and may be considered for the next farm bill, expected in 2018. There are four main types of inaccuracy and misconduct in SNAP: • Trafficking SNAP benefits is the illicit sale of SNAP benefits, which can involve both retailers and recipients. • Retailer application fraud generally involves an illicit attempt by a store owner to participate in SNAP when the store or owner is not eligible. • Errors and fraud by households applying for SNAP benefits can result in improper payments. Errors are unintentional, while fraud is the intentional violation of program rules. • Errors and fraud by state agencies--agency errors can result in inadvertent improper payments; the discussion of agency fraud largely focuses on certain states' Quality Control (QC) misconduct. Certain key ideas are fundamental to any discussion of SNAP errors and fraud: • Errors are not the same as fraud. Fraud is intentional activity that breaks federal and/or state laws, while errors can be the result of unintentional mistakes. Certain acts, such as trafficking SNAP benefits, are always considered fraud; other acts, such as duplicate enrollment, may be the result of either error or fraud depending on the circumstances of the case. • SNAP fraud is rare, according to all available data and reports. • There is no single measure that reflects all the forms of fraud in SNAP. There are some frequently cited measures that capture some part of the issue, and there are relevant data from federal and state agencies' enforcement efforts. The most frequently cited measure of fraud is the national retailer trafficking rate, which, most recently, estimated that 1.50% of SNAP benefits redeemed from FY2012-FY2014 were trafficked. While the national retailer trafficking rate (which is issued roughly every three years) estimates the extent of retailer trafficking, there is not a standard recipient trafficking rate, nor is there an overall recipient fraud rate. USDA-FNS is responsible for identifying stores engaged in retailer trafficking--using transaction data analysis, undercover investigations, and other tools--and punishing store owners. Retailers found to have trafficked may be subject to permanent disqualification from participation in SNAP, fines, and other penalties. USDA-FNS also works to identify fraud by retailers applying to accept SNAP benefits. Retailers found to have falsified their applications may be subject to denial, permanent disqualification, and other penalties. While retailer trafficking and retailer application fraud are primarily pursued by a single federal entity (USDA-FNS), recipient violations (i.e., recipient trafficking and recipient application fraud) are pursued by 53 different state agencies. Recipients found to have trafficked may be required to repay the amount trafficked and may be subject to disqualification from receiving SNAP benefits and other penalties. State agencies' efforts to reduce and punish recipient fraud vary, which is evident, for instance, in state- submitted data on recipient disqualification activities. The national payment error rate (NPER) is the most-often cited measure of nationwide payment accuracy. Using USDA-FNS's Quality Control (QC) system, the NPER estimates states' accuracy in determining eligibility and benefit amounts. The NPER has limitations, though; for instance, it only reflects errors above a threshold amount ($38 in FY2017). In FY2014, it was estimated that 3.66% of SNAP benefit issuance was improper--including a 2.96% overpayment rate and a 0.69% underpayment rate. Regardless of the cause of an overpayment, SNAP agencies are required to work toward recovering excess benefits from households that were overpaid (this is referred to as "establishing a claim against a household"). In FY2014, according to USDA-FNS's FY2014 State Activity Report and Annual Quality Control Report, an estimated $2.1 billion in benefits were overpaid, an estimated $500 million in benefits were underpaid, and about $575 million in claims were established by states to recover overpayments. USDA-FNS identified data quality issues that prevented the publication of an NPER in FY2015 and FY2016, but USDAFNS expects to publish an NPER for FY2017 in June 2018. Overpayments and underpayments to households can be the result of recipient errors, recipient fraud, or agency errors during the certification process. State agencies rely on household-provided information in applications, but also employ a range of data matches--some required by federal law, some optional that vary by state--to promote and double-check information. According to the USDA-FNS FY2016 State Activity Report, of states' established claims for overpayment, approximately 62% of overpayment claim dollars were for recipient errors, about 28% were for agency errors, and about 11% were due to recipient fraud. In addition to inadvertent agency errors, state agencies and their agents have been involved in isolated instances of fraud. Beyond cases of fraud conducted by state agency employees for personal gain, in FY2017 the Department of Justice obtained False Claim Act settlements from three state agencies accused of falsifying their Quality Control data and unlawfully obtaining federal bonuses. Investigations into this matter, conducted by the USDA Office of the Inspector General (USDA-OIG), are ongoing. Across all types of fraud, oversight entities such as the Government Accountability Office and USDA-OIG have identified issues and strategies relevant to combating errors and fraud in SNAP. USDA-FNS has also proposed related regulatory changes that were not finalized. On the retailer side, issues identified focus on opportunities to prevent and more promptly punish trafficking. On the recipient side, issues identified include the nonexistence of a recipient fraud rate, states varied levels of anti-fraud effort (which may be better incentivized), and improvements to data matching in the application process. Changes that strengthen payment accuracy and punishments against fraud can be in tension with other policy objectives such as preserving recipient access to the program, and may have unintended consequences such as incurring costs greater than their savings. Balancing program objectives such as these are considerations for policymakers in this area. [ABSTRACT FROM AUTHOR]