The IRS lacks an effective means of keeping track of paper case files, sometimes hampering its litigation and forcing it to abandon revenue claims, a Government Accountability Office study found. In two audits by the GAO, the IRS couldn’t produce between 10% and 14% of the case files requested. In a similar check by the Treasury Inspector General for Tax Administration, the IRS was unable to come up with 19% of requested case files. Paper case files are generated by audits, examinations and court cases. In each of several court cases, the IRS lost $40,000 in revenue because it could not locate case files, the GAO said. Moreover, the IRS doesn’t track its performance in retrieving files and transmitting them promptly or analyze why they go missing, the GAO said. In response, the IRS said it will review its record management program and take corrective measures.