Thornton continues to advise several ongoing studies of programs and policies to assist people with disabilities participate fully in economic and community life. These include the Social Security Administration's Ticket to Work program and Youth Transition Demonstration. He has studied how well managed care and care-management efforts serve people with disabilities as well as how modifications to the Medicare and Medicaid programs could support better integration and health for people with disabilities. His experience includes designing and implementing large multisite demonstration evaluations and conducting process, impact, and benefit-costs analyses.

Thornton has published widely in peer-reviewed journals, such as Health Services Research, Journal of Vocational Rehabilitation, American Sociological Review, and Journal of Policy Analysis and Management. In addition, he has served on many expert panels as well as on the boards of directors of Mathematica and of the Center for Studying Health System Change. He has a Ph.D. in economics from the Johns Hopkins University.