It is pretty clear from many other threads that top-heavy compensation is full plan-year compensation. However, should the full plan year include time during the year in which the employee was a union employee? The plan for non-union employees is top-heavy. A union employee becomes a non-union employee during the plan year and immediately participates in the non-union plan. Should this participant's top-heavy contribution be based on time both as a union employee and as a non-union employee, or only time worked while a non-union employee?

This is no different than a plan with dual entry. TH is still on full year pay, so it would be on full year pay for change in status.