Broadened Scope of ERISA Fiduciary Rules After several years of debate and revision, a Department of Labor (DOL) regulation, revising the definition of a “fiduciary” as it applied to investment managers, became applicable on June 9, 2017. The new regulation expands the definition of “fiduciary” under the Employee Retirement Income Security Act of 1974 (ERISA) and the Internal Revenue Code of 1986, as amended, to …