Southern Illinois Healthcare Foundation (SIHF) provides a branch of adult focused medicine solely for men and women aged 18 years and older. A specific concentration of medicine that many of our doctors specialize in is called Internal Medicine. Internal medicine doctors focus on the prevention, detection, and treatment of non-surgical diseases in adults. SIHF office locations accept most medical insurance plans including Medicare and Medicaid, as well as an affordable sliding fee scale for individuals who are not medically insured. To find out more about SIHF sites that offer adult medicine, please click on a link to one our sites below: