- Form 5500 - If you maintain an employee benefit plan, such as a pension, profit-sharing, or stock bonus plan, file Form 5500 or Form 5500-SF for calendar year 2019. If you use a fiscal year as your plan year, file the form by the last day of the seventh month after the plan's year end. The maximum extension period for Form 5500 and Form 5500SF is 2.5 months (or October 15 for calendar-year plans).