I think you need to get new elections, there is no basis for defaulting to an election made under a plan of another employer that was terminated before it became part of the acquiring company. If they wanted to do something like that, it should have been discussed and determined during due diligence, and could easily have been accomplished by simply merging the acquired company's plan into the acquirer's plan. Why was that not considered? Also, and I could very well be wrong, but I don't think you're prohibited from terminating a 401(k) plan in this instance, it's just that the plan termination is not a distributable event and you must transfer funds to the successor plan. If they were worried about going to employees for new elections, wanting to treat as the same plan for them, then merging or terminating and transferring certainly is consistent with that philosophy. Regardless, those horses are already out of the barn and you need to give them all new saddles (deferral elections). IMHO