Under Title I of the Employee Retirement Income Security Act of 1974 (ERISA), employers are permitted to sponsor two broad categories of pension plans. They are (1) defined benefit plans-in which employers generally maintain a fund to provide a fixed level of monthly retirement income based on a formula specified in the plan-or (2) defined contribution plans-in which retirement income is based on employer and employee contributions and the performance of investments in individual employee accounts. 6 These experts included a representative of a pension consumer rights organization; a representative of a nonprofit, nonpartisan, retirement research organization; representatives of a private law firm specializing in employee benefits; representatives of a membership organization dedicated to retirement plan professionals; and the author of a book and journal article on multiple employer benefit arrangements. A MEP may be a defined benefit plan or a defined contribution plan.