Lou S gave you the right answer. But if they are taking RMDs, they are obviously over the NRA. Most plans have (or should have) a provision that allows "in service distributions" to those who are working past NRA. If it was important, this participant could take a full distribution, and roll it over to an IRA (after taking the RMD for the current year). Then, most of his RMD will come from his IRA (where, if there are more than one, he CAN aggregate). Of course, if there are ongoing contributions to the plan, he will still have little RMDs that will be required based on the new money going into the plan.