Cohen is a nationally recognized divorce attorney, holding an adjunct professorship at the
University of Pennsylvania Law School. In 1969 he left to become the co-founder of another firm, In 2003, Cohen started Cohen Lans LLP, which in 2011 merged with Clair, Greifer LLP to form Cohen Clair Lans Greifer & Thorpe LLP. Both predecessor firms had been named among Best Law Firms by
U.S. News & World Report in its 2010 inaugural edition, and Cohen Clair Lans Greifer & Thorpe has been named "Best" in each subsequent year. He lectures throughout the United States and in Europe. Cohen represented
Julie Roy in her medical malpractice case against psychoanalyst Renatus Hartogs in 1975. The case was notable for being the first successful lawsuit brought upon by a woman against her former therapist for inappropriate sexual relations. In 2016, Governor Cuomo named Cohen Chairperson of the Judicial Screening Committee for the First Judicial Department, a Committee he has been a member of since 2012. He was also designated as a member of the State Judicial Screening Committee by the Governor in 2016. He was appointed in 2016 by Judge Peter H. Moulton, Administrative Judge at that time of the Supreme Court, New York County, as Chairperson of that Court’s Matrimonial Committee. In 2018, Cohen was reappointed to that position by Judge Deborah A. Kaplan who succeeded Judge Moulton as Administrative Judge. In 2019 he was also appointed by Justice Alan D. Scheinkman as Special Master in the Alternative Dispute Resolution Pilot Program in the Second Judicial Department. In 2019 he was appointed by Presiding Justice Rolando T. Acosta to the Appellate Division, Attorney Grievance Committee for the First Judicial Department. All of the appointments are in New York State. Since 2003, Cohen has served as an
adjunct professor of law at the
University of Pennsylvania School of Law where he teaches a course entitled "Anatomy of a Divorce." He is a former JAG officer and member of
JAG Corps, representing members of the military and their families. Cohen has been principal attorney in a number of high-profile, high-net-worth divorces for clients in a variety of industries, including finance, entertainment, real estate and politics, in New York and other states across the country.
Christie Brinkley, Swedish countess Marie Douglas-David,
James Gandolfini,
Dina Lohan,
Marla Maples,
Tommy Mottola,
Athina Onassis, Charlotte Sarkozy,
Uma Thurman, and
Ivana Trump. Cohen's book,
Reconcilable Differences: Seven Essential Tips to Remaining Together from a Top Matrimonial Lawyer, was published in 2002. In 2024, he was named one of "America's Top 200 Lawyers" by
Forbes. ==Personal life==