Cancer is the second most common cause of death in the United States. In addition to primary prevention of cancer, such as smoking cessation counseling, early detection of cancer is a key part of our national strategy to reduce cancer deaths. Despite effective screening tests for colon, cervical, breast, and lung cancer, many patients who might benefit are still not being screened as recommended. Many factors contribute to underuse of cancer screening. For example, sometimes physicians’ forget to order screening when they are caring for patients with a large number of other health issues, and sometimes tests are recommended but not completed by patients because of fear, cost, or lack of awareness of the benefits. Our research helps health care teams and policy-makers understand the causes of underuse and develop solutions to improve care.