Form 5500 is an annual report that certain retirement plans must file to share key details with the IRS and Department of Labor. It’s mainly used by businesses that offer retirement plans to multiple employees, such as a 401k, and helps ensure the plan is following the rules and being managed properly. The form includes information about the plan’s finances, participants, and any fees or service providers. Filing Form 5500 is required for most large or multi-employee plans, and it must be submitted electronically. Smaller plans, like Solo 401ks with no employees other than a spouse, usually don’t need to file this version and may use a simpler version called Form 5500-EZ instead.