To obtain the 2.5 month extension for the Form 5500, one must file which form?

To obtain a 2.5 month extension for filing the Form 5500, an entity must file Form 5558. This form is specifically designed to request an extension for certain employee benefit plan filings, including the annual Form 5500. When this form is submitted timely, it permits an extension of the filing deadline, allowing for additional time to prepare and submit the required documentation.

The other forms listed do not serve this purpose. For example, Form 5000 is not a recognized form relevant to this context, nor is Form 8800 related to filing extensions for employee benefit plans. Meanwhile, Form 1040 is for individual income tax returns and also does not pertain to the extension of Form 5500. Therefore, knowing that Form 5558 is the correct choice underscores its specific relevance in the context of extending deadlines for these particular filings.