Anyone have any experience with welfare plans that go back and forth across the 100 participant threshold? Do you get letters from IRS or DOL in the "under 100" years when you don't file a 5500?

Use codes 4R and 4S for item 8b on page 2 of the Form 5500:

4R - Unfunded, fully insured, or combination unfunded/insured welfare plan that will not file a Form 5500 for next plan year pursuant to 29 CFR 2520.104-20.
4S - Unfunded, fully insured, or combination unfunded/insured welfare plan that stopped filing Form 5500s in an earlier plan year pursuant to 29 CFR 2520.104-20.

A few questions here.

Rather than using 4S a few years down the line, why not go back and amend the year that did not use 4R and enter 4R?

Also, for a plan that filed 4R, say the participant count stays below 100 and a few years later the company is sold and there is no more welfare plan. Does a 5500 get filed for that year with 'Final' checked off, or you just don't file anymore?

And, for a plan that was incorrectly filed as Final but should have been filed as 4R, should it be amended?

I was hoping someone might have some thoughts on my posting above, particularly my last question since I think we should file an amended form but I wanted to hear some other thoughts.