revised Medicare from a system of fee-for-service (FFS) payments to PPS, under which hospitals receive a fixed amount for each patient with a given diagnosis. Other insurers also limited what hospitals could charge. The result was a financial squeeze on hospitals, compelling them to seek new ways to manage their costs. In specifically exempting GPOs from the Federal Anti-Kickback Law, many healthcare providers interpreted the act as an encouragement to the expansion of GPOs. Congress did not specify any limit on contract administration fees, but required the United States Department of Health and Human Services (HHS) to monitor such fees for possible abuse – particularly with respect to fees in excess of 3.0 percent. In 1991, HHS promulgated safe harbor regulations, reflecting Congress’ intent to permit contract administration fees and creating the additional safeguard that GPOs inform members of administrative fees in excess of 3.0 percent. Despite these safeguards, the Government Accounting Office (GAO) published a study in 2002 indicating that GPOs did not always in fact reduce the cost of supplies and equipment for hospitals, but in some cases increased these costs by as much as 37%. Further examining the practices of GPOs, the Federal Trade Commission (FTC) clarified that "safety zone thresholds do not prevent and should not be appropriately read as preventing antitrust challenges to any of the alleged anticompetitive contracting practices..." of GPOs. In 2002, the Senate Judiciary Committee's Antitrust Subcommittee imposed stricter standards on GPOs in healthcare, requiring the adoption of a Code of Conduct to which GPOs must subscribe. Critics of GPOs charge that, as long as GPOs receive fees from the vendors they are charged with policing, the industry has anti-competitive contracting potential that should be subjected to further scrutiny and/or regulation. Vertical-market GPO A vertical GPO assists companies and organizations within a specific industry or market segment. Healthcare GPO A healthcare group purchasing organization (GPO) assists in promoting quality healthcare relief and assists diverse providers in effectively managing expenses. A GPO aggregates the purchasing volume of its members for various goods and services and develops contracts with suppliers through which members may buy at group price and terms if they choose to. GPOs typically provide contracted discounts on medical supplies, nutrition, pharmacy and laboratory. Some of the large GPOs have expanded contract portfolios to also offer discounts on office supplies and non-medical related services. A GPO's earnings come from an "Administrative" fee.