b 401(k) Plan moved to a Pooled Employer Plan

A new client who has Engaged my office to provide Consulting Services, has a 401(k) plan since 2001, and now wants to move to a Pooled Employer Plan.  Where can I find detailed information regarding the transfer, along with the applicable Notices, potential Black-out period, etc.  As one knows if a 401(k) plan is terminated a new one cannot be started immediately as a 12 month waiting period is in play.  How does the preceding impact the transfer to a Pooled Employer Plan.  There does not appear to be enough information to properly advise one's client on how to proceed.  

The client can work with the PEP to merge the client's existing 401(k) into the PEP.  Essentially, the client will adopt the PEP's version of a Participating Employer Agreement and coordinate with the PEP the transfer of assets to the PEP.  If the merger and transfer will take more than 3 business days, then a black-out period will be required.

This model is being by one of the larger PEPs which also happens to be a payroll provider:

https://www.plansponsor.com/in-depth/mechanics-moving-pep/

Single employer plan is merging into a PEP. If mid-plan year, important to make sure there are no benefit cutbacks. Important to make sure all protected benefits in the single employer plan carry forward to the PEP. Single employer plan would need to file a final Form 5500 and report that all assets transferred to another qualified plan. Assuming HCEs and keys benefitted under both plans offered by the same Employer, all testing would be as if one plan for the entire plan year (required aggregation). I'm not sure if the pre-approved document providers' software offers amendments to document the merger of a plan into another, but you'd want a solid paper trail on what happened to the prior single employer plan (why did the CODA stop for example). I don't see how anyone could argue that "terminating" the single employer plan is appropriate. I'd consider the PEP a successor plan to the single employer plan, thus wondering how the single employer plan supported distributable events (which is what the article above seemed to suggest).  

Almost all "transfers" of a single employer 401k plan moving into a PEP are Plan Mergers, not Plan Terminations. I've never had one that was a "termination". 

No step-up in vesting, no "distributable event" for the prior plan. Adoption into a PEP will constitute a "restatement" of the prior plan, btw. No need to restate a plan as long as it is handled before the restatement deadline via the plan merger.

On the final Form 5500 for the single employer plan, it should indicate the name of the successor plan, EIN of the PEP Plan Sponsor (PPP). Testing is aggregated for the full year. Annual 402(g) limits still apply (no "double dipping" in deferrals....). 

Lots of moving parts in a PEP. Proceed with caution if you haven't done any.