Illinoisans looking to go back to HealthCare.gov to buy health insurance for next year will find higher prices in many parts of the state. Those who want to change plans have until Monday to make that decision and for people in Springfield, Decatur and Belleville, for example, it will mean higher premiums. In addition to higher monthly premiums, consumers in some parts of the state could see the deductibles rising on their plans if they decide to keep them. Competition among insurance companies in the Chicago area has led to a slight decline in premiums.