Is signature required on the "Credit Life Insurance Disclosure" if the borrower does not purchase the insurance?

It's not required when the insurance is refused, but it's a good idea to have a signature showing the borrower doesn't want it.

If the disclosure you're referring to is the Reg Z disclosure, you don't want a signature that says they want it at a price of $0.00. As pointed out, it can be very helpful to have the signature on something that says they do NOT want the insurance. I've seen too many cases where a borrower dies and the family thinks there was credit insurance in place as, "He said he was getting it" or "He always bought it so he must have on this loan." Having a signature on the refusal is the best way to stop those arguments.