Notifying IRS if TIN no longer active?

Since I have virtually no information to go on, this question may not make any sense. A governmental employer who has a "deferred compensation" plan - I'm guessing a 457(b)??? is apparently either changing or terminating the plan, whatever the plan is. We got a call out of the blue asking how they notify the IRS that the TIN will be "inactive."

I don't work with governmental 457 plans, or any other governmental "deferred compensation" plans for that matter, if there are such things.

Does anyone have any idea if there is a required notification to the IRS of such a TIN becoming inactive? I believe if a corporation terminates/dissolves there is a notification process involving the corporate EIN, but that's a different matter.

Thanks in advance, if you know anything about this.

I just looked at this for a somewhat different purpose, and there does not seem to be any procedure or interest on part of IRS for a taxpayer to notify it that an EIN is dead,  and IRS will never reassign. There is some info here:https://www.irs.gov/businesses/small-businesses-self-employed/canceling-an-ein-closing-your-account

If it is not filing 5500s---initially filed an exemption certificate and therefore is exempt from such filings, there would be no need to tell IRS  of a change or plan termination in any event.