The controlled group rules, basically say that in many circumstances, companies with similar ownership will be considered as one company. The rules were put in place to stop abuses of excluding rank-and-file employees from retirement coverage while benefiting the highly compensated.
When your plan provider explains the rules to you, they’re trying to screw you out of some humongous retirement benefit, they’re just parroting a law that has been on the books to prevent retirement plan discrimination in favor of highly compensated employees.
