215 ILCS 110/29
Every subscription certificate made by a dental service plan corporation shall provide for the payment for dental services as therein specified for a period of 12 months from the date of issue of the subscription certificate. Any such contract may provide that it shall ordinarily be renewed from year to year, unless there has been one month's prior written notice of termination either by the subscriber or by the corporation. During the first contract year the provisions of the contract may provide that the inception of coverage may be deferred for not more than 2 months from date of issue of the contract and may exclude treatment for illness or other condition requiring dental service existing at the inception of the contract.
215 ILCS 110/29