Mr. Kosner, a graduate of the University of Miami Law School and the University of Kansas, lives in Chicago, where he has been practicing law since 1998. After graduating from Miami, he practiced in southern Florida before returning to Chicago; he was raised in the northern suburbs. He runs his own practice, The Kosner Firm, which he chartered in 2003 to support his vision of the way personal injury clients should be cared for.

In 2005, at the age of 35, Mr. Kosner effectuated one of the largest stillbirth settlements in Illinois history. The case was settled in fewer than 90 days from the time he started working on it.

In 2009, Mr. Kosner settled the second largest wrongful death/medical malpractice case ever against Cook County Hospital. The settlement of $9.8 million was achieved just over two years after the filing of the lawsuit. The average medical malpractice case in Cook County takes more than three years to resolve.

Mr. Kosner is a member of the Illinois and Florida Bar Associations. A devoted family man, he is married and has two children.