Individual Practice Association. A partnership, corporation or other legal entity which contracts with an HMO, union or other provider to provide care to an enrolled group for a fixed monthly amount. In the IPA, the provider can work from his office instead of an HMO center or clinic. Fee-for-service patients can be treated alongside those in the IPA plan. Patients in the IPA plan must use a participating provider. The provider must follow IPA practices, accept reimbursement as full payment and comply with IPA peer review 'and quality assurance procedures. Typically, the IPA pays the provider a percentage of his fee, with the remaining percentage held in a reserve pool that may be divided at year's end by the provider if any funds remain.