Indiana Code Title 27. Insurance § 27-5.1-2-37

(1) The written notice must be delivered or mailed to the policyholder at the last known address of the policyholder.

(2) The written notice must specify the effective date of the cancellation.

(3) Upon request of the policyholder, the written notice must be accompanied by a written explanation of the specific reasons for the cancellation.

(1) ten (10) days before canceling the insurance policy, if the cancellation is for nonpayment of premium;

(2) twenty (20) days before canceling the insurance policy, if the cancellation occurs more than sixty (60) days after the date of issuance of the policy;  and

(3) ten (10) days before canceling the insurance policy, if the cancellation occurs less than sixty-one (61) days after the date of issuance of the policy.