Need to know extension timeframe for a terminating plan

Terminating Plan: 01/01/2022 to 10/17/2022

When is the due date for filing Form 5558 Extension?

So the plan was terminated 10/17/2022. When were the assets distributed? If not until 2023, then the 2022 year is still a full year.

But that would still mean 7/31/2023 would be the deadline for filing the extension.

Asset has not been distributed yet. So, extension will be 10/15/2023, right?

If it was filed timely, an extension to 10/16/23 could be requested for a calendar year 2022 plan.

If a 5558 was not filed by 7/31, your next option is to check if the corporate (or personal) tax return was put on extension, in which case the 5500 can be extended on that basis, but you'll need a copy.