Following the National Cancer Institute's National Lung Screening Trial, guidelines were released initially in 2012 by the National Comprehensive Cancer Network, an alliance of twenty one cancer centers in the United States. Their consensus guidelines, which are updated annually, support screening as a process, not a single test, and discuss risks and benefits of screening in high risk individuals within a comprehensive multidisciplinary program. Screening is only recommended for individuals defined as high risk meeting specific criteria. More details can be found in their patient guidelines. While lung cancer screening programs have been supported by the NCCN, International Association for the Study of Lung Cancer (IASLC), American Cancer Society, The American Society of Clinical Oncology (ASCO), and other organizations, the costs of screening may not be covered by medical insurance policies, unless the eligibility criteria specified by the Centers for Medicare and Medicaid Services (CMS) are met.