Corporate Officers

President and Chief Information Security Officer

As the President of ARC, Mr. Trapnell provides leadership that supports the organization’s mission of delivering innovative and trustworthy analyses informed by decades of experience and practical expertise while providing our employees with a collegial, inspiring, and supportive workplace.

Mr. Trapnell also serves as the company’s Chief Information Security Officer (CISO), leveraging his experience working with managed information security and secure network products. Mr. Trapnell is an ISC2 Certified Information Systems Security Professional (CISSP).

Mr. Trapnell was previously a Vice President at ARC responsible for implementation, improvement, and design of systems, implementation of policies and procedures, overall quality assurance, business development, and short and long-term strategic planning. Prior to his position as a vice president, Mr. Trapnell served in a number of roles including the ARC Chief Operations Officer and the Director of Business Development.

A health policy expert with over twenty years of experience working with government health insurance initiatives, Mr. Trapnell continues to lead projects, actively manage deliverables and perform health care modeling and actuarial analysis for a number of ARC clients. Mr. Trapnell is the project director for ARC’s Actuarial Research and Design Services (ARDS) contract with the Center for Medicare and Medicaid Innovation (CMMI) and the IDIQ Program Director for ARC’s RMADA 2 IDIQ contract with CMS. Mr. Trapnell also oversees a number of ARC’s design, implementation and analytic support projects within the Center for Medicare and Medicaid Innovation.

Mr. Trapnell holds a Master of Public Policy from the University of Maryland, Baltimore County, a Master of Science in History from the University of Edinburgh, and a dual Bachelors degree in Mathematics and History from Bowdoin College.

Executive Vice President

Dan Waldo joined ARC as a senior economist in December 2008, after a 34-year career in the U.S. Government Civil Service. Mr. Waldo designs and implements computer models to analyze the effects of changes in health policy and helps to support demonstration operations and evaluation through claims analysis.

Prior to joining ARC, Mr. Waldo held a number of positions in the Centers for Medicare and Medicaid Services, including acting director of the Office of Strategic Planning. His technical activities were concentrated in measurement of health care financing in general and of the Federal Medicare program in particular. Mr. Waldo was the architect of the Reagan Administration actuarial cost estimates of the Medicare Catastrophic Coverage Act drug benefit and was part of the HCFA Office of the Actuary team providing cost estimates for the Clinton Administration health reform initiative. He has provided technical assistance to the World Bank, the World Health Organization, and the Organization for Economic Cooperation in the development of frameworks for measuring and tracking health expenditure.

Mr. Waldo holds a M.A. degree in economics from the University of Wisconsin and completed the academic requirements for a Ph.D. degree in public policy from the University of Maryland – Baltimore County.

Vice President for Strategic Operations

Dr. Greenwald joined ARC in 2023, following a 21-year career at RTI International and a 12-year career at the Health Care Financing Administration (now the Centers for Medicare and Medicaid Services).  Over her more than 30-year career, Dr. Greenwald has achieved recognition as an expert in alternative health care system payment models. Her areas of expertise include health care reform design and modeling, organizational strategic planning and performance monitoring, Medicare Fee for Service and Medicare Advantage payment and delivery systems, payment model innovation and program evaluation.

She has led numerous health care innovation model program evaluations, including CMS sponsored evaluations of the State Innovation Models 1 and 2, as well as the first Evaluation of the Medicare All Payer Model. Dr. Greenwald has worked directly in the development of new Medicare care payment models, including risk adjustment, pay for performance and value-based purchasing.

Dr. Greenwald holds a Ph.D. in Government/Economics from the University of Virginia, an M.P.A from University of Virginia, and an A.B. in from Dartmouth College.

Chief Financial Officer

Shelly Windsor joined ARC in 1990. She has over 26 years of experience leading the direction and oversight of financial, administrative, and human resource functions. This includes accounting, contracts, finance, forecasting, budgeting, compliance, employee benefits, and proposal development. She has a B.S. in business administration from Stayer College. She completed her accounting coursework at the University of Virginia and is a Certified Public Accountant in the Commonwealth of Virginia.

Founder and Chairman of the Board

Gordon R. Trapnell is a nationally recognized expert in analyzing the feasibility and estimating the cost of private and public insurance programs. He has prepared cost estimates for major new federal insurance initiatives, providing the data needed by public officials to reach important policy decisions. His analysis has served as the basis for evaluating the major national health insurance proposals developed by the Administration and Congress.

Mr. Trapnell has extensive experience analyzing the actuarial problems faced by public sector insurance and employee benefit programs, especially Medicaid and Medicare. He has been retained by the Congressional Budget Office by every Administration in the past 40 years and by a variety of other interested parties to analyze the cost and financial impacts of major proposals to change the financing of U.S. health care. His estimates have also been used to analyze the impact of proposals to reform small group and individual health insurance markets.

Mr. Trapnell is a Fellow of the Society of Actuaries and Member of the American Academy of Actuaries. He holds a B.S. degree in mathematics from the University of Virginia and completed preliminary examinations for a Ph.D. in finance and health economics at the Massachusetts Institute of Technology.