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Michael L. Baum

Michael L. Baum is a senior partner of Wisner Baum (formerly Baum Hedlund Aristei & Goldman) based in Los Angeles. For 29 years, Michael was the managing partner of Baum Hedlund until he turned over the reins to R. Brent Wisner at the beginning of 2023. 

Under Michael’s stewardship, our firm grew from a small boutique law firm to one of the nation’s leading plaintiffs’ litigation firms that is now known for its cutting edge, superior legal work. While running Baum Hedlund, the firm’s success in challenging cases and precedent-setting legal rulings has helped shape the law for the benefit of those harmed in commercial transportation accidents and by dangerous pharmaceuticals and consumer products. Michael’s ceaseless advocacy in pharmaceutical and consumer fraud litigation has brought our firm international attention and acclaim. 

“When I became an attorney in 1985, we were the new kids on the block. We only had dreams of achieving the success we now enjoy,” Michael Baum says. “Our ethos from the beginning was pure and simple: we wanted to use the law to help people who had been wronged and make the world a better place. As much as we have grown over the years, that philosophy has remained, and out of it grew a culture that has attracted talented lawyers like Brent who share the same mission. He is exactly the kind of lawyer and leader that will take this firm to new heights. Wisner Baum is in good hands.”

Our firm has won billions under Michael’s leadership  in consumer fraud and product liability cases against some of the world’s largest pharmaceutical and life sciences corporations, including Bayer Corp. (Monsanto), Eli Lilly, Forest Labs, GlaxoSmithKline, and Pfizer, among many others. 

As a sophisticated legal team, the firm has helped uncover harmful drug industry practices, chemical manufacturer misconduct and deceptive marketing schemes which have resulted in groundbreaking verdicts, major consumer safety advocacy and improved drug warning labels.

Michael has also successfully led the firm through thousands of wrongful death and personal injury cases stemming from mass disasters. These include structure fire and wildfire litigation. His experience litigating fire cases began in 1987 when he worked on the Dupont Plaza Hotel arson case, one of the deadliest hotel fires in U.S. history. He also helped litigate hundreds of homeowner and business claims that resulted in lost structures that burned down in Malibu, California as a result of the 2018 Woolsey Fire.

Michael L. BAUM Attorney, Senior Partner

Locally & Nationally Recognized

The firm was one of the first law firms in the country to take on Roundup (glyphosate) weed killer cancer cases against Monsanto. Michael and his colleagues served on the trial teams for the first three Roundup trials against Monsanto (Bayer), resulting in $2.424 billion in jury verdicts for the plaintiffs. These trial victories paved the way for settlement resolutions in 2020 worth a combined $10.9 billion, a major milestone for Baum Hedlund and the culmination of more than four years of hard work and perseverance. 

During the litigation, his team obtained a trove of internal documents known as the Monsanto Papers, which they ensured were declassified and released to regulatory agencies, scientists, and the general public. With invitations from lawmakers in these countries, Michael traveled with his partner Brent Wisner, to the EU and Canada to brief regulators on the key evidence uncovered in the Monsanto litigation. His influence on public policy concerning Roundup led Politico to choose Michael as one of five "changemakers" in the world making waves in pesticides policy. 

Career Highlights

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