Bill's answer is likely correct, but i wanted to point to another issue that he did not address. What kind of business transaction was it? If it was an asset sale and all employees went to work for the buyer, then they had no service after the sale and there is likely little information after your termination date. If it's a stock sale, then employment continues after the sale, and this point is moot. In that case, it just depends on what the plan and the termination documentation say about the accrual of rights after the termination of the plan.