Mary Katherine Hayburn, Associate

Mary Katherine Hayburn, Associate

Divorce and Family Law

Separation and Divorce

Child Custody and Support

Premarital Agreements

T 301.656.8850 Ext. 427

F 301.656.3053

7735 Old Georgetown Road
Suite 1100
Bethesda, MD 20814-6130


B.A., University of Pennsylvania

J.D., American University’s Washington School of Law

Bar Admissions


District of Columbia


Mary Katherine Hayburn is an attorney in the Divorce and Family Law Group. She has been practicing law since 2005, focusing on family law since 2007. She joined Pasternak & Fidis in 2013 after having worked in private practice in several Montgomery County, Maryland, law firms. Mary Katherine is licensed to practice in Maryland, Washington, D.C. and Virginia. She has handled cases in trial courts all over the state of Maryland as well as in the Superior Court of the District of Columbia. In 2014 she took and passed the Virginia Bar and now handles family law cases in Northern Virginia as well.

Mary Katherine represents clients facing a wide-range of family law issues, including divorce, resolution of post-divorce disputes, and dissolution of nonmarital relationships. She has extensive experience resolving disputes relating to children, including legal and physical custody, modification of custody, access schedules, supervised visitation, same-sex custody issues, parental relocation, mental illness and substance abuse, child support, and matters involving adult disabled children. Her experience in family law includes property division, alimony claims, contempt proceedings, interstate disputes, enforcement actions, appeals, and drafting premarital agreements, postmarital agreements and marital settlement agreements.

Mary Katherine works closely with her clients to develop an approach to resolving their matters that is tailored to each client’s particular needs and objectives. Because she understands that a domestic dispute can have a long-term effect on the entire family, she helps her clients seek solutions that preserve family relationships and minimize the damage to children and to her clients’ economic security. She is experienced at negotiation, mediation and handling all aspects of settlement. Mary Katherine is also trained to represent clients who choose the collaborative law model to resolve their matters. She is an experienced courtroom lawyer and can take her client’s case to trial when necessary.

Mary Katherine graduated from the University of Pennsylvania where she studied Russian and sociology. She received her law degree from American University’s Washington College of Law. As a law student she had her first experiences with family law while working with the university’s domestic violence clinic.

A native of Philadelphia, Mary Katherine now calls Virginia home. When not working, she loves spending her free time pursuing active outdoor adventures. Her favorite activities include hiking, rafting, kayaking, biking and visiting adventure parks. She is always looking for a new challenge.

Activities and Affiliations

  • Bar Association of Montgomery County, Maryland
  • Maryland State Bar Association
  • Women’s Bar Association of Maryland


  • Montgomery County Family Law Magistrates Panel, co-moderator


  • Co-author of Family Law Jurisdictional Comparisons, 2d (Maryland/Washington, DC chapter), European Lawyer/Thomson Reuters

Blog Posts

September 10, 2015

New Divorce Laws in Maryland

Three amendments to Maryland’s divorce laws will take effect on October 1, 2015 and will make the divorce process easier and less expensive for many people. The most significant is the addition of a new ground for absolute divorce. Currently, the only no-fault ground for divorce is 12-month separation. The person requesting the divorce must bring a third-party witness to court to corroborate the separation and certain other matters. Currently, under Maryland law, one party must move out of the marital home to start the 12-month separation period.

The amendment will allow parties to obtain a divorce based on mutual consent provided they have a written agreement resolving all property and spousal support issues (which neither has moved to set aside) and that there are… MORE >

October 1, 2013

The Fate of Frozen Embryos When a Couple Divorces

John and Rita were married for five years when John was diagnosed with cancer. The couple then arranged to harvest and store embryos, using Rita’s eggs and John’s sperm, in case John’s cancer treatment rendered him sterile. The cancer treatment is successful, but John becomes sterile. The marriage then fails. John wants to keep the frozen embryos and have them implanted in a surrogate. He desperately wants a biological child and sees this as his only opportunity. Rita no longer wants to parent a child with John, and she does not want to have a biological child with whom she has no relationship.

Mike and Steve are married in a state where same-sex partners can legally marry. They plan to begin a family. Each donates his… MORE >