Multiple CGs in one plan--how to test

[BG5150]

Say I have 5 companies that all adopted a plan: A, B, C, D, E, F

The CG's are:

A B & C are one CG

D & E are another

A B & D also

C & E too

F is not part of any CG or ASG, so I have a MEP.

Do I need to do 5 separate tests?

[EBECatty]

There have been some prior threads on this, including one I believe I started, and my recollection is there's not one perfectly clear answer. 

Some take the position that belonging to an overlapping group makes an employer part of one larger group, which in your example would continue to grow. Because A, B, and C are related, and C and E are related, then A, B, C, and E are all one employer. If that's true, because D and E are related, and A, B, C, and E are related, then A, B, C, D, and E are all one employer. I suppose F would be separate in any event if unrelated to every other entity. This is the approach taken in Who's the Employer. 

Others take the position, maybe more as a practical alternative, that you test each group separately, which would give you five tests. I have heard from several TPAs who test using this approach.