Watch live: HHS Secretary Robert F. Kennedy Jr. testifies before House Appropriations Committee

Nearly four months into his new job, Kennedy Jr. is set to testify on May 14 before a pair of Congressional committees who are expected to grill one of President Donald Trump's highest-profile Cabinet members on a range of controversial topics – from proposed budget cuts to his flip-flop on vaccinations as a preventative tool during the nation's measles outbreak.

Kennedy, who has a history of making controversial remarks about vaccines, recently backed vaccination as a preventive tool during a measles outbreak, but noted that vaccines should be left to parents' discretion. He's recently rolled out plans to remove artificial food dyes from the U.S. food supply.

Members of the House Appropriations Committee and the Senate Health, Education, Labor and Pensions Committee are likely to question him about drastic cuts to programs and staffing at Health and Human Services, the department he heads. They may also tackle his push to ban fluoride from drinking water.

President Trump’s $1.7 trillion “skinny budget” proposal for fiscal year 2026 reduces non-defense spending by 23% compared with 2025. The budget seeks $94 billion for the Department of Health and Human Services agencies, a reduction of about 26% from the 2025 level and cuts programs and staff at agencies, including the National Institutes of Health and the Centers for Disease Control and Prevention