The DI program was established in 1956 to provide monthly cash benefits to individuals unable to work because of severe long-term disability. In fiscal year 2010, the program’s average monthly benefit was about $922. To be eligible for benefits, workers with disabilities must have a specified number of recent work credits under Social Security when they acquired a disability. Individuals may also be able to qualify based on the work record of a deceased or retired parent with a disability or a deceased spouse. Benefits are financed by payroll taxes paid into the DI Trust Fund by covered workers and their employers and are based on a worker’s earnings history. To meet the definition of disability under the DI program, an individual must have a medically determinable physical or mental impairment that (1) has lasted or is expected to last at least 1 year or to result in death and (2) prevents the individual from engaging in SGA. Individuals are engaged in SGA if they have earnings that average more than $1,000 per month in calendar year 2010, after applying any work incentives. Program guidelines direct DI beneficiaries to report their earnings to SSA in a timely manner to ensure they are still eligible for benefits and do not incur an overpayment. SSA has several programs that are designed to assist beneficiaries in returning to work. For example, the Ticket to Work and Work Incentives Improvement Act of 1999 provided for the establishment of the Ticket to Work and Self-Sufficiency Program to provide eligible DI and Supplemental Security Income (SSI) beneficiaries with employment services, vocational rehabilitation services, or other support services to help them obtain and retain employment and reduce their dependency on benefits. SSA provides each eligible beneficiary with a ticket to obtain services from SSA-approved public or private providers, referred to as employment networks, or from traditional state vocational rehabilitation agencies. SSA conducts work CDRs to determine if beneficiaries are still eligible or are working above the SGA level. Work CDRs are event-driven and initiated when there is an indication of work activity. While work CDRs can be prompted by several events, most are generated by SSA’s enforcement operation. This process involves periodic data matches between SSA’s MBR database and IRS earnings data. The enforcement operation generates alerts for cases that exceed specified earnings thresholds, which are then forwarded to one of eight processing centers for additional development by staff. In fiscal year 2010, the enforcement operation identified approximately 2 million records of which more than 531,000 were sent to SSA’s processing centers and field offices for review. Appendix I provides detailed information on the results of the enforcement operation for fiscal years 2008 to 2010, which used IRS earnings data from 2007 to 2009 (enforcement matches are typically conducted using the prior year’s earnings data). Work CDRs can also be triggered by other events, such as beneficiaries reporting their earnings to SSA. For example, SSA requires beneficiaries to undergo periodic medical reviews called medical continuing disability reviews, or medical CDRs, to assess whether they continue to have a disabling impairment. During such reviews, the disability examiner sometimes discovers evidence that a beneficiary is working and forwards the case to an SSA field office or processing center for earnings or work development. Third-party reports from state vocational rehabilitation agencies, federal agencies, or anonymous individuals may also trigger a work CDR. Finally, some DI beneficiaries report their earnings to SSA as directed under program guidelines by visiting an SSA field office or calling the agency’s 800 number. While most work CDRs are initially sent to processing centers as a result of action by SSA’s enforcement operation, some of these cases are later referred to one of SSA’s more than 1,300 field offices. Field offices can be asked to assist processing centers in the development of cases when obtaining local information about beneficiaries or their employers would expedite case processing. Field offices also tend to be the focal points for work CDRs generated by medical CDRs, third-party reporting, and beneficiary self-reporting. Work CDRs entail processes that can be both labor-intensive and time-consuming. For each case, SSA staff must review electronic case files in SSA’s eWork and associated data systems, conduct interviews, and contact beneficiaries and their employers to verify earnings and any applicable work incentives, such as subsidies or impairment-related work expenses. After the initial review of cases indicating a cessation of benefits, a “disability processing specialist” or “disability examiner” determines whether benefits should be discontinued and an overpayment assessed. (Fig. 1 provides an overview of the work CDR process.) When a DI work-related overpayment is identified, the beneficiary is notified of the overpayment and may request reconsideration or waiver of that overpayment. SSA may grant a waiver request if the agency finds the beneficiary was not at fault and recovery or adjustment would either defeat the purpose of the program or be against equity and good conscience, as defined by SSA. If SSA denies a reconsideration or waiver request, full repayment is requested. If the beneficiary is receiving DI or certain other SSA benefits, SSA may withhold partial payment of these benefits to recover the debt. However, if no SSA benefits are being received, or if the beneficiary asserts that the proposed withholding amount is too large, the agency generally requests repayment over 12 to 36 months. SSA policy requires a minimum monthly payment of $10 dollars. SSA may also attempt to recover payments due from the individual’s estate or subsequent survivor’s benefits. (Fig. 2 provides an overview of SSA’s debt recovery system.) The agency uses the ROAR system to track DI overpayments and collections. When a debtor is no longer receiving benefits, SSA can also recover debt through several external collection tools. When a beneficiary is not repaying as agreed in the repayment plan, SSA terminates its collection activity and, after a due process period, the debt is referred for external collection. External debt collection tools include tax refund offset, which withholds or reduces federal tax refunds; federal salary offset, which withholds or reduces wages and payments to a federal employee;  administrative offset (against other than SSA benefits), which withholds or reduces federal payments other than tax refunds or salary;  administrative wage garnishment, which garnishes wages and payments paid by private employers or state and local governments; and credit bureau referral, which refers delinquent accounts to credit bureaus. Once a debt is referred to external collection, the debtor remains subject to offsets until the debt is repaid in full or other resolution of the case. Medical and work-related overpayments in the DI program detected by SSA grew from about $860 million in fiscal year 2001 to about $1.4 billion in fiscal year 2010, and though the true extent of overpayments due to earnings is currently unknown, our review suggests that most of them are related to beneficiaries who work above SGA while receiving benefits. (Fig. 3 shows the increase in overpayments detected by SSA in recent years.) SSA officials estimate that from fiscal years 2005 through 2009, about 72 percent of all projected DI overpayments were work-related, meaning the overpayments were to beneficiaries who returned to work and were no longer eligible. This figure is higher than cited in past years by SSA. SSA officials attribute the increase in the percentage of overpayments that are work-related during this period to improved detection by its enforcement operation, and to changes in how the agency estimates the overpayment numbers. Agency officials also explained that approximately half of the increase in overpayment dollars during this period may be due to the increase in DI program benefit levels. We found that detected overpayments could be even larger than SSA’s data reflect because some overpayments have been accidentally removed from SSA records due to manual processing errors. In our review of 60 work CDR cases, we found two manual processing errors which resulted in overpayments totaling $53,097 being removed from agency records. In one case, staff entered a code to correct an overpayment amount but instead deleted the overpayment entirely. As a result of our detection, SSA officials reentered the overpayment debts into the system and indicated they would proceed with debtor notification and recovery. Because the results of our case review are not generalizable, the incidence of such occurrences is currently unknown and thus the potential impact on total DI overpayments owed by ineligible beneficiaries is not clear. SSA officials said that they do not have a mechanism for detecting, or a process of supervisory review to catch, such processing errors. In the 60 cases we reviewed, we also found that individual overpayment amounts varied widely, ranging from $1,126 to $53,436, with a median of $16,917 per individual. The size of individual overpayments can also be affected by SSA’s Automated Earnings Reappraisal Operations (AERO), which is a computer program that periodically screens a beneficiary’s earnings record for changes, and uses that information to adjust, as needed, the monthly benefit amount. Of the 60 cases, we found 54 in which AERO increases in benefit amount occurred even while SSA conducted a work CDR to determine if the beneficiary was still eligible for benefits at all. In addition, an individual overpayment can result in additional overpayments to dependents (family members who receive benefits). In 8 of the 60 cases, additional overpayments occurred because the primary beneficiary had dependents. For example, in one case, the overpayments to two dependent children added $6,580 to the primary beneficiary’s existing overpayment debt of $17,102, for a total of $23,682 owed. A beneficiary’s total DI overpayment debt can also increase because of multiple periods of employment. DI beneficiaries may reenter and leave the workforce based on their ability to perform SGA.