In July 2015, the Annals of Internal Medicine published an independent cost-analysis of the American Board of Internal Medicine's Maintenance of Certification program.[24] Using simulation modeling of the entire American Board of Internal Medicine-certified workforce of US physicians, researchers from the University of California San Francisco and Stanford University estimated that the Feb 2015 version of American Board of Internal Medicine Maintenance of Certification would cost $5.7 billion over ten years, including $561 million in American Board of Internal Medicine's fees and $5.1 billion in time costs (arising from 32.7 million physician hours spent completing Maintenance of Certification requirements). Internists will incur an average of $23,607 (95% CI, $5,380 to $66,383) in Maintenance of Certification costs over 10 years, ranging from $16,725 for general internists to $40,495 for hematologists-oncologists. The authors concluded that "A rigorous evaluation of its effect on clinical and economic outcomes is warranted to balance potential gains in health care quality and efficiency against the high costs identified in this study."[25]