H&W - separate businesses - one plan?

Husband owns his S corp, Wife owns her S corp.  Business are not related (different fields).  Can one DB plan cover both H&W?  State NC.  Just trying to keep the admin cost on a low side.

Does either business have an employee beyond the shareholder-employee?

no, each business is owner-only, both H&Q are in professional services but different fields.

Why couldn't they have a multiple employer plan?

34 minutes ago, truphao said:

Business are not related (different fields).

But are they related under the meaning of 414(b), (c), or (m)? Being in different professional fields is indicative, but not determinative.

that is essentially what my question is?   They are not partnership, they are not ASG, but are they a CG?

The answer is yes, one DBP can cover them both, but the question is whether you have a single employer plan of a control group or affiliated service group (in which case you HAVE to have one plan covering both) or a multiple employer plan for which your reporting is a little different. If you don't have a CG under the new rules or an ASG, but want one, have one make the other an employee for a nominal salary.

Spouses are usually attributed each other's ownership for controlled group purposes, unless they meet the requirements to be exempt. The requirements to be exempt from attribution are described in IRC 1563(e)(5) - does it apply in your case?

If they want to be in a controlled group, it should be pretty easy to make that happen. Personally I am of the opinion that collaborating on a retirement benefit program rises to the level of being involved in the management of each other's business, so just the fact they are both talking to you about adopting a plan together probably makes them lose the exemption. But if you wanted to be more formal about it, you could have one of them hire the other (and pay them a salary), or put each other on their company's board of directors.

Thank you all - this gave me enough to formulate my thoughts.  Tremendously appreciative, as always.