Marilyn A. Lion, is a corporate partner, Co-Chair of the firm’s Financial Institutions Group, and a member of the firm’s Corporate Department.

Ms. Lion focuses on corporate transactions in the insurance industry, including mergers and acquisitions and financing transactions, as well as insurance and reinsurance regulatory matters.

Ms. Lion was selected by The Deal as one of its “Top Women in Dealmaking” in 2023. She is recognized as a leading practitioner for Insurance: Transactional & Regulatory in Chambers USA (2024), where she is said to bring “an incredible command of the insurance business and its financial underpinnings to her practice.” Sources also note that she is “very creative” and “outstanding.” In previous editions of the guide, clients who describe her as “always thoughtful,” “a good problem solver,” “collaborative” and “resourceful,” also value her “deep industry knowledge.” They highlight her strength in reinsurance matters and report that “she is very constructive in terms of getting deals done.” They note “she’s absolutely stellar - whip smart, terrific in court and a joy to be around.” She is said to be “thorough and thoughtful in every analysis,” “always responsive and attuned to client needs,” and “one of the smartest lawyers I have ever had the pleasure of working with.” She is also recognized as a Leading Lawyer for insurance in The Legal 500 US (2024), which has noted that she has “very deep insurance industry expertise.” Ms. Lion is listed as a Notable Practitioner for Insurance by IFLR1000 (2022) and was named a Rising Star in insurance by Law360 (2016) and by Super Lawyers.

Ms. Lion joined the firm in 2005. She received a J.D. from Harvard Law School in 2005. Ms. Lion received a B.A. summa cum laude from the University of Pennsylvania in 2001. Prior to law school, Ms. Lion worked as an actuarial associate at AXA Equitable Life Insurance Company.

Ms. Lion is the editor, and a co-author, of the Insurance and Investment Management M&A Deskbook (Practising Law Institute, 2023). She is also the co-author of numerous articles, including “How Shareholder Activists Are Targeting Insurers,” Law360 (November, 2023); “Thoughts on financing and capital solutions for insurance companies,” Westlaw (October, 2022); “The Legal 500: Insurance & Reinsurance Country Comparative Guide,” The In-House Lawyer (April, 2017); “Developments At The NAIC Spring Meeting,” Law360 (April, 2016); “Report On The NAIC 2015 Summer National Meeting,” FC&S Legal (November, 2015); “A Closer Look,” Best's Review (June, 2015); “NAIC 2015 Spring National Meeting,” Insurance Coverage Law Report (May/June, 2015); “IAIS Issues Consultation On Global Insurance Capital Standard,” Canadian Insurance Regulation Reporter (February, 2015); “Rector-Modified Recommendations to NAIC Task Force on Financing of XXX and AXXX Reserves,” FC&S Legal (August, 2014); “Citing Private Equity Concerns, New York Department of Financial Services Proposes Increased Scrutiny and Disclosure for Acquisitions of New York Domestic and Commercially Domiciled Insurers,” FC&S Legal (June, 2014); and “Report on the NAIC 2014 Spring National Meeting,” FC&S Legal’s “Eye on the Experts” blog (April, 2014).  

Ms. Lion is a member of the Bars of New York and New Jersey.


  • Harvard Law School, 2005, J.D.
  • University of Pennsylvania, 2001, B.A.

Bar Admissions

  • New Jersey
  • New York