Mergers and GUST

[Guest slt]

What happens when a plan that is not amended for GUST is merged into a plan that has been amended for GUST. I understand the normal merger rules (where I must preserve accrued benefits, optional forms, actuarial factors, etc.) but what about the effective dates? For example, the surviving plan was amended for GUST over a year ago. Therefore, for some provisions, it has an effective date that would be earlier than a plan that was amended for GUST right now (e.g., the "greater of" requirement for GATT changes - determining actuarial equivalence - to comply with 411(d)(6) would end earlier for the plan already amended for GUST). Any ideas? My thought is that the merged plan that does not survive would no longer have a separate existence, so I shouldn't even worry about this - as long as the effective dates are correct for the surviving plan that has already been amended. However, counsel is telling me that I may have to worry about this. Any thoughts? As always, I greatly appreciate the help I get from everyone on these boards!

I also posted this message on the Mergers Board. Thanks.