Small employers must treat all employees the same.
They must offer the same benefits and same contributions to similarly situated employees. They cannot contribute more, for instance, to owners or managers than they do for rank-and-file employees.
They can offer multiple options, and the effect of selecting a lower option might mean a lower contribution, but everyone has to have the same opportunity to enroll in the richer plan with the higher contribution amount.
They can vary contributions based on length of service. uWhatever their contribution strategy, they cannot discriminate in favor of highly compensated employees if they have a 125 plan in place.