401k Controlled Group - One company has no plan

Hello, thank you in advance for your help with this. 

Situation: Company A, Owner A has 100% ownership. Company B, same Owner A has 85% ownership. Both companies have around 10 employees.

Company A has offered a 401k since 2017, converted to SH 401k in 2019.

Company B does not have any 401k

Am I correct that Company A and B are in a controlled group and the 401k should have been offered to Company B since inception? If so, what is the mechanism to correct this? Would company B employees be due the SH contributions over the last 2 years?

Thank you

When did the common ownership occur?

Does the 15% owner of Company B work for Company B?

Way more information is needed. Don't assume anything at this point. For example, has this ownership been the same for all years, including 2017? Was company B acquired in a 410(b)(6)(C) transaction, so that a transition period might apply? Are all of the employees ELIGIBLE employees? Perfectly ok to exclude some or all employees of a Controlled group IF you can pass coverage testing.

Based upon the ownership you give above, it would appear to be a controlled group now.

Owner A has had the same ownership percentage in both companies for many years. No acquisition.

The other owners of Company B are investors, they don't work for the company. Owner A does not take a salary from either company.

And of course, make sure your plan document doesn't contain language requiring it to cover EVERY member of the controlled group.

(There's nothing STANDARD about a standardized plan document!)  😁