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.Most employersponsored retirement plans are subject to ERISA requirements. Reporting and Disclosure Guide for Employee Benefit Plans, Meeting Your Fiduciary Responsibilities, Selecting an Auditor for your Employee Benefit 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). Complying with ERISA's various disclosure requirements, such as the requirement to provide each employee with a summary plan description.