[8] From 2009 to 2014, Bremberg was the department manager and top health policy expert for MITRE,[9] a not-for-profit organization that provides services to the United States government.

MITRE manages Federally Funded Research and Development Centers (FFRDCs) supporting the Department of Defense (DOD), the Federal Aviation Administration (FAA), the Internal Revenue Service (IRS), the Department of Veterans Affairs (VA), the Department of Homeland Security (DHS), the Administrative Office of the U.S. Courts on behalf of the Federal Judiciary, the Centers for Medicare and Medicaid Services (CMS), and the National Institute of Standards and Technology (NIST).

[11][12] During the 2016 election cycle, Bremberg served as the policy director for the GOP Platform Committee.

[13] Bremberg was later the leader of President-elect Donald Trump's transition team for Health and Human Services.

Bremberg, alongside Marc Short and Rick Dearborn, coordinated with aides of Senator Mitch McConnell in employing the Congressional Review Act to reverse 13 regulations made late in the presidency of Barack Obama by creating an Excel spreadsheet of targets, eventually being able to eliminate over twice as many regulations as they had anticipated.