Is anyone aware of any support for the position that the interest credits that an employee who continues working past normal retirement age receives under a cash balance plan could be the equivalent of the actuarial adjustment required when benefits are suspended without meeting the suspension of benefits notice requirements?

I believe that this depends on whether post-NRA interest credits are considered part of the accrued benefit. I'm aware of the cases saying that pre-NRA interest credits are part of the accrued benefit for employees who are vested under the plan, but I haven't found anything that addresses the post-NRA employee. My guess is that no such guidance exists, but I'd appreciate any info or thoughts you might have.

Take a situation where the interest rate used to determine the actuarial adjustment post NRA with respect to suspension of benefits exceeds the rate used to credit interest on the cash balance account. If the position can't be argued successfully in that example, I don't see how it can be argued successfully in general.