For guidance on what may cause a 403(b) plan to be subject to ERISA, please consult the Department of Labor's rules. All 403(b) plans are subject to Title I of ERISA unless an exemption applies.403(b) plan sponsors that match elective deferrals are generally required to test the matching contributions via the actual contribution percentage test (ACP). Reporting and Disclosure Guide for Employee Benefit Plans, Meeting Your Fiduciary Responsibilities, Selecting an Auditor for your Employee Benefit Plan. Most employersponsored retirement plans are subject to ERISA requirements. Regulatory changes require all ERISA 403(b) plans to file expanded 5500 packages to the. Internal Revenue Service (IRS) and Department of Labor (DOL).