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Advocates for NJ and PA
Workers & Their Families

Partners and Counsel of Costello & Mains, LLC

Miriam S. Edelstein



Mount Laurel Township, NJ



Miriam S. Edelstein joined Costello & Mains, LLC in 2020 following twelve years of counseling employers, management and Human Resources professionals on the full range of workplace legal issues under federal, state and local laws. Miriam's approach to advising employers was grounded in her core passion for social justice and fairness for individuals. As management counsel, she was in a position to advise those in power on ethically sound, legally compliant, best workplace practices.

In addition to legal counsel, Miriam also developed and delivered workplace trainings and programs striving to incorporate and strengthen principles of diversity, equity and inclusion into her clients' workplaces. Having worked on several pro bono matters for Lambda Legal Defense & Education Fund, the nation's oldest and largest non-profit focused on the advancement of rights and protections for LGBTQ+ individuals, Miriam joined Lambda Legal at its headquarters in New York City as its Director of Strategic Partner Programs. When she returned to her private law practice, Miriam continued these training efforts with her clients as a natural enhancement to providing ethical workplace advice.

Now, at Costello & Mains, Miriam advocates directly for individuals - both in the workplace and in society at large. Drawing on her prior experience representing companies and organizations across industries and sectors, ranging in size from small, start-ups to multinational, Fortune 20 corporations, Miriam's deep substantive knowledge of employment and civil rights laws is rounded out by her practical knowledge of how employers work.

Miriam graduated from Hampshire College in Amherst, Massachusetts with a Bachelor of Arts in Theater and obtained her Juris Doctor from Temple University's Beasley School of Law in 2006. Apart from her time at Lambda Legal, Miriam worked in private practice, focused on management-side Labor & Employment law at AmLaw 100 firm Reed Smith, LLP as well as with Chubb Insurance.

Miriam's employment law experience runs the gamut from harassment/discrimination to wage/hour actions, and has practiced in courts and administrative agencies across New Jersey, New York and Pennsylvania. She is admitted to the bar in all three of those states, as well as to practice before the United States District Courts for the District of New Jersey, Eastern District of Pennsylvania, Middle District of Pennsylvania, Western District of Pennsylvania, Eastern District of New York and the United States Court of Appeals for the Third Circuit.

Miriam is highly active in the New Jersey Association for Justice, where she serves on the Board of Governors and as a member of the Diversity, Equity & Inclusion Committee, the Education Committee, the Civil Rights Committee and the Women Trial Lawyers Caucus. She regularly presents on substantive and procedural legal topics in civil litigation as well as DE&I issues in the legal profession. She is also a member of the National LGBTQ+ Bar Association, the Philadelphia Bar Association and a former Commissioner of the American Bar Association's Sexual Orientation and Gender Identity Commission.

She has authored several articles and provided commentary for legal and business publications on topics in employment law, civil litigation and DE&I issues. She is most passionate about her outreach efforts to increase diversity among legal professionals and policy-makers of the future by educating undergraduate students at Temple University about civics, workers' rights and civil rights.

Bar Admissions

  • Pennsylvania
  • New Jersey
  • U.S. District Court Eastern District of Pennsylvania
  • U.S. District Court District of New Jersey
  • U.S. Court of Appeals 3rd Circuit
  • U.S. District Court Middle District of Pennsylvania
  • New York
  • U.S. District Court Western District of Pennsylvania
  • U.S. District Court Eastern District of New York


  • Temple University James E. Beasley School of Law, Philadelphia, Pennsylvania
    • J.D. - 2006
    • Honors: Recipient of Law Faculty Scholarship
    • Honors: Recipient of Honorable Louis C. Bechtle Scholarship
    • Honors: Member of Temple’s National Trial Team
    • Honors: Received the Wapner, Newman, Wigrizer & Brecher Award for trial advocacy
    • Honors: Lena L. Hale Award
  • Hampshire College
    • B.A. - 2001
    • Major: Theatre