We are in a second position in a participation loan. Is CIP and identification required for the guarantors of the loan? The lead bank would obviously have done their due diligence but just need clarification of our position.

CIP applies to the lead bank, but not to participating banks. refer to §103.121(a)(1)(ii)(B).

Do you need to have a letter from the Lead bank stating they have a CIP program & are gathering information?

That's a dangerous statement to make. They are supposed to do due diligence, but I would not say obviously.

I know the CIP is not required if you purchase a participation, but we ask for a copy of the CIP from the original lender anyway. What can it hurt? So far, we have had no objection, and we are reasonably sure we are covered if questions arise later.