In the United States, a group purchasing organization (GPO) is an entity that is created to leverage the purchasing power of a group of businesses to obtain discounts from vendors based on the collective buying power of the GPO members.

Many GPOs are funded by administrative fees that are paid by the vendors that GPOs oversee. Some GPOs are funded by fees paid by the buying members. Some GPOs are funded by a combination of both of these methods. These fees can be set as a percentage of the purchase or set as an annual flat rate. Some GPOs set mandatory participation levels for their members, while others are completely voluntary. Members participate based on their purchasing needs and their level of confidence in what should be competitive pricing negotiated by their GPOs.

Group purchasing is used in many industries to purchase raw materials and supplies, but it is common practice in the grocery industry, health care, electronics, industrial manufacturing and agricultural industries. In recent years, group purchasing has begun to take root in the nonprofit community. Group purchasing amongst nonprofits is still relatively new, but is quickly becoming common place as nonprofits aim to find ways to reduce overhead expenses. In the healthcare field, GPOs have most commonly been accessed by acute-care organizations, but non-profit Community Clinics and Health Centers throughout the U.S. have also been engaging in group purchasing.