Is CIP required on the beneficiary of a trust at the time the check is written to the beneficiary?

Not unless the beneficiary becomes a customer of yours...…….

I can envision a situation, depending on how your state laws work, where a totten trust, which passes $ on death, could make the beneficiary a customer once a death certificate is presented if they choose to be a customer at that point.

On the bank side certain checking accounts are set up where the beneficiary becomes the owner - this would be different than a trust account correct?

Not necessarily, a totten trust is a trust. The simple answer to your first question is... only when the beneficiary becomes a customer of the bank..