The following tax returns are due on July 31, 2019:
Employee Benefit Plans: Form 5500 series (or Form 5558 for a 3-month extension).
Please note that this applies to calendar year filers only. If your year end is not December 31st, you are a fiscal year filer and your due date is different.
For employee benefit plans that are fiscal year filers, the due date is the last day of the 7th month following the close of the tax year.