The AICPA Employee Benefit Plan Audit Quality Center has developed this primer to provide a general understanding of employee benefit plan parties in interest and prohibited transactions under the Employee Retirement Income Security Act of 1974 (ERISA). This primer explains how a party in interest under ERISA may differ from a related party as that term is defined by generally accepted accounting principles (GAAP). This primer discusses party in interest transactions that are prohibited under ERISA and administrative actions of the Department of Labor (DOL), as well as statutory and administrative class and individual exemptions. This primer also discusses how exemptions may be requested, the reporting requirements for party in interest and non-exempt transactions, applicable penalties imposed by ERISA or the Internal Revenue Code (IRC), and the Voluntary Fiduciary Correction (VFC) Program. A list of references to additional resources is included at the end of this primer.