Marilyn A. Lion, based in the firm's New York office, is a member of the Corporate Department and the Financial Institutions Group. She 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 is also a member of the Board of Governors of the Association of Life Insurance Counsel.

Ms. Lion is recognized as a leading practitioner for Insurance: Transactional & Regulatory in Chambers USA (2021), where clients highlight her strength in reinsurance matters and report that “she is very constructive in terms of getting deals done.” In previous editions of the guide, they note “she’s absolutely stellar - whip smart, terrific in court and a joy to be around,” she is praised as being “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 Next Generation Partner for insurance in The Legal 500 US (2021), which has noted that she has “very deep insurance industry expertise.” Ms. Lion is listed as a Notable Practitioner for Insurance by IFLR1000 (2020) 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, 2015). She is also the co-author of numerous articles, including “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