Can a terminated participant "contribute" his life insurance premiums into a qualified plan? In the past, the premiums were paid from his existing account in the trust, be this year, he deposited his premiums into the trust.

Does the plan expressly authorize those actions?

I'm not sure what you mean by "he deposited his premiums into the trust" but I assume he paid his premiums with a personal check.

Essentially, this would be an after-tax voluntary contribution. Possibly permitted in the plan document but not likely.

Even if the plan allowed for post tax contributions, would it allow them for a terminated employee/participant...I doubt it.

TBob - good point. Somehow I missed that he was term'd. Ugh; not much hope.