Stock Acquisition and Successor Plan

Company A is acquiring Company B via stock acquisition.  Both companies currently sponsor retirement plans.  Company A has a stand alone plan and Company B is part of a PEO.  Once the acquisition happens  Company B will retain their own EIN and act as a subsidiary of Company A.   The intent is for Company B to terminate participation in the PEO plan prior to acquisition.   Post acquisition Company B will become a participating employer on the Company A plan.

The question is does Company B employees have a distributable event or would participation in Company A plan be viewed as a successor plan? 

No, i don't think it would be a successor plan: I think that the reason why it's suggested to terminate a plan prior to stock sale is to eliminate the successor plan issue  

The employees of the PEO are terminating employment there and are experiencing a distributable event as a result.   Ask employees of Company B to rollover into Company A's plan.