For guidance on what may cause a 403(b) plan to be subject to ERISA, please consult the Department of Labor's rules. Each Form 5500 must accurately reflect the characteristics and operations that applied during the reporting year of the plan or arrangement.All 403(b) plans are subject to Title I of ERISA unless an exemption applies. Summary of ERISA Regulations, Opinions, and Court Decisions, Section 3 Definitions (Selected), Section 4 Plans Covered, Section 404 Fiduciary Duties. Chapter 9 provides blank worksheets that you will need to accurately and actively participate in your 403(b) plan. Regulatory changes require all ERISA 403(b) plans to file expanded 5500 packages to the. Internal Revenue Service (IRS) and Department of Labor (DOL). The IRS plans to issue additional guidance for LTPT rules, including proposed regulations for ERISA 403(b) plans.