Can anyone direct me or advise me on this question?

I have a partnership with 2 partners - each owning 50% of the partnership although profits are not split in this manner. One partner of the partnership is the owner of a single member LLC with one employee at present - perhaps more in the future. Does the 401(k) plan of the partnership have to include any employees of the LLC? I can't seem to find a definitive answer because any reference to brother sister groups refer to corporations and I'm not sure that it applies to the partnership and/or the LLC.

Any guidance is greatly appreciated!

Controlled groups can include unincorporated businesses.

On the facts you have provided there doesn't appear to be a controlled group.

A owns 50% of AB partnership
A owns 100% of A LLC

That doesn't fit into the definition of parent/subsidiary or brother/sister.


Beware of affiliated service group rules.