Scully received his B.A. from the University of Virginia in 1979 and his J.D. from Catholic University in 1986. Scully began his political career by working for US Senator Slade Gorton from 1980 to 1985. Scully then served as an attorney with Akin, Gump, Strauss, Hauer & Feld LLP from 1985 to 1988. In 1988, Scully joined the presidential campaign of President George H. W. Bush. Following that, he worked at the White House as Deputy Assistant to the President and Counselor to the Director of the Office of Management and Budget (OMB) from 1992 to 1993; and as Associate Director of OMB for Human Resources, Veterans and Labor from 1989 to 1992.
Scully, then, reentered private practice with the Washington, D.C. law firm of Patton Boggs, LLP, where he focused on regulatory and legislative work in health care. In his next role, Scully served as President and CEO of the Federation of American Hospitals from 1995 to 2001. The Federation represents over 1,500 privately owned and managed hospitals. It was from this position that Scully was nominated and confirmed as CMS Administrator. In this role, Scully served as the top executive in the management of Medicare, Medicaid, the State Children's Health Insurance Program, and other national health care initiatives.
On December 8, 2003, President George W. Bush signed the Medicare Prescription Drug, Improvement, and Modernization Act. Scully's role in the passage of this legislation is perhaps his most notable achievement while at CMS. The bill's most important provision was a prescription drug benefit for Medicare, known as Medicare Part D. Under Part D, Medicare beneficiaries can receive prescription drug coverage through private insurance plans that are then reimbursed by CMS. Scully had fought for prescription drug coverage throughout his time at CMS beginning with an effort to create a discount prescription drug card. That effort was blocked by lawsuits from the major pharmacy chains that claimed that CMS did not have the statutory authority to create the program.
In his first speech as CMS Administrator, Scully announced that Medicare would begin collecting and publishing quality data on health care providers across the country including hospitals, nursing homes, home health agencies and dialysis centers. The program began with the reporting of quality measures for nursing homes in a handful of states. In those states, 78 percent of the nursing homes reported that they tried to improve, according to CMS. The next step for the program was the publication of performance by nursing homes nationwide on 10 measures ranging from the percentage of residents with pressure sores to those in physical restraints. A $700,000 advertising campaign publicizing the measures began in conjunction with the release of the data. The intention of the program was to provide consumers with a comparison of nursing homes while encouraging the homes to get better, according to a statement by Scully at the time. Critics of the program complained that nursing homes were being asked to do additional work in order to report the measures while they were dealing with funding cutbacks.
In July 2003, Scully announced that CMS would begin paying bonuses to hospitals that scored well on 35 quality measures. Hospitals nationwide would vie for $7 million in higher reimbursement by providing superior care for five conditions: heart attack, heart failure, pneumonia, coronary artery bypass surgery, and hip and knee replacements. In addition, CMS posted report cards on the hospitals' performance on the public CMS website. The program was hailed as large step towards improving the American health care system by leading to a more rational health care pricing system.
Scully also initiated a broad public education campaign to improve seniors’ awareness and utilization of their Medicare benefits. The US$30 million publicly funded advertising campaign called, "Helping You Help Yourself" was designed to inform Medicare beneficiaries about the Medicare web site and toll-free phone number, which could answer their questions about health care plans.
On July 1, 2001, Scully presided over his agency's name change: the Health Care Financing Administration would now be called the Centers for Medicare and Medicaid Services.
In 2006, Scully led the investment and development in Member Health, the 3d largest pharmacy benefit manager (PBM) in the country, which was subsequently purchased by CVS Health. In 2013, Scully founded naviHealth, now a Cardinal Health Company. In 2015, Scully led the investment and development in Innovage, the country's largest and leading Program of All-Inclusive Care for the Elderly (PACE). He currently sits on the boards of Dartmouth Geisel School of Medicine, the Batten School of Leadership and Public Policy, the Alliance for Health Policy, and the George H.W. Bush Presidential Library at Texas A&M.