Since arriving at Foley Hoag, Thomas has focused his practice on Medicare and Medicaid reimbursement issues for innovator pharmaceutical products; provided legal, regulatory and strategic advice for multiple Medicare and Medicaid providers, including large dialysis organizations, long-term care providers, medical device manufacturers and hospitals; provided crisis counseling and ongoing legal advice to Medicare Advantage and Medicare Part D plans undergoing CMS audits; counseled hospital clients on the requirements of the Emergency Medical Treatment and Labor Act (EMTALA); and, with the enactment of the ACA in the Spring of 2010, is actively counseling clients on the multiple changes to health care laws that have occurred and will occur as a result of the legislation, especially in the context of health reform Exchange implementation and the legal obligation of employers as a result of enactment of the law.

Thomas also provides pro-bono services on behalf of support organizations representing North Korean refugees living in the United States and Seoul, South Korea. He specializes in helping refugees who are in need of health care.

Prior to coming to Foley Hoag, Thomas served in a succession of high-level federal health care policy positions throughout the Bush Administration. In 2008, he served as acting General Counsel of HHS; from 2005 – 2008, he served as health policy advisor under HHS Secretary Michael Leavitt. While serving as acting General Counsel, Thomas oversaw a staff of some 450 attorneys responsible for reviewing every regulation and interpretive guidance published by the Department. In that role, he provided legal advice to Secretary Leavitt, along with the Administrator of CMS and Commissioner of the Food and Drug Administration.

Thomas played a key role in the implementation of every major health policy initiative enacted during his time at HHS, including the Medicare Prescription Drug Benefit (Medicare Part D). He also chaired HHS policy briefings on Medicare and Medicaid policy.

While at HHS Thomas served as the administration's lead negotiator with Congress on Medicare and Medicaid
provisions in the Deficit Reduction Act of 2005; drafted President Bush's Executive Order on health care transparency and health information technology; served as HHS negotiator on the pharmaceutical and medical device provisions of the U.S.-South Korea Free Trade Agreement; developed health care initiatives for the President's State of the Union Addresses in 2007 and 2008; was principal liaison between HHS and the Department of Treasury on tax issues for health care; and served as a collaborator in the Health Care Forum as part of the Strategic Economic Dialogue with the Chinese government.

Thomas also directed the conduct of litigation involving provider reimbursement disputes, including drafting a request for a writ of certiorari before the U.S. Supreme Court on a hospital reimbursement matter. As acting General Counsel at HHS, he was on the FDA's amicus brief in Wyeth v. Levine, the prescription drug preemption case decided by the U.S. Supreme Court in 2009.

Prior to his service at HHS, Thomas was regulatory counsel to the Massachusetts Hospital Association during the 1990s. He is a member of the adjunct faculties of the George Washington University School of Public Health and Health Services and Suffolk University School of Law.