Kate Kostrzewa, Esq.



Kate Kostrzewa’s practice focuses exclusively on Estate Planning, Estate Administration and Probate Proceedings. She is committed to providing her clients with quality legal services, to direct and clear communication and reasonable pricing.

Practice Areas

  • Estate Planning
  • Estate Administration
  • Probate Proceedings
  • Foreign Language Clients (Spanish, Portuguese and French)

Kate is the Principal Attorney at KDK Legal, with a practice focusing on Estate Planning, Estate Administration and Probate Proceedings. Kate trained in tax during law school and has, for many years, prepared Estate Planning documents for her Estate Planning clients. Prior to dedicating herself full-time to Estate Planning, Kate spent many years providing clients with comprehensive civil litigation services to resolve disputes involving employment law, business law, real estate law, municipal law and probate contests. Kate has worked on behalf of private individuals, private organizations and public entities. Kate’s language skills (Spanish, Portuguese and French) allow her to serve a diverse array of clients whose primary language is not English.

Kate has been a member of the California State Bar in Good Standing since 1990.  She has also been a member of the San Mateo County Bar Association throughout much of her career. Kate served on the Board of the San Mateo County Bar Association Women Lawyers’ Section from 2016 to 2022. The Women Lawyers’ Section, among other activities, offers continuing education programs addressing issues relevant to female attorneys and sponsors the Spring and Holiday Luncheons honoring San Mateo County Judges.     

During her many years in practice, Kate has performed Pro Bono legal work on behalf of low income clients, including victims of domestic violence. She has volunteered as a “judge” in the San Mateo County Mock Trial Competition and the Hastings College of the Law Moot Court program. In 1999, Kate spent two weeks in Honduras on a Hurricane Mitch Relief Aid Program transporting and distributing food, clothing and medical supplies to hurricane victims on the Mosquito Coast. Kate served as Treasurer of the Coastside Mothers’ Club in 2014 and 2015. She volunteers weekly in her child’s classroom to assist the teacher with math centers. Kate also helps to organize and fund-raise for scholarships for an After-School Spanish Program that offers elementary aged school children one-hour of Spanish language class each week. Kate is currently an active member of the Half Moon Bay Chamber of Commerce.

  • Ph.D., University of Texas at Austin (Sociology with Specialization in Demography) 
  • J.D., University of California at Los Angeles School of Law
  • International Rotary Foundation Scholar, Faculté du Droit, Université de Grenoble, France
  • B.A., University of California at Berkeley (English)
  • Education Abroad Program, Facultad de Filosofía y Letras, Universidad Complutense de Madrid, Spain 

OUTDOOR ACTIVITIES: Hiking, Biking, Camping, Backpacking, Boating, Snow-Shoeing and more!

SPORTS: Kate played competitive soccer in High School and College. Now, she cheers on professional and collegiate Bay Area sports teams.

MUSIC: Kate listens to a broad range of musical styles but her preferred genres are latin jazz, rock and world music.

TRAVEL: Kate has visited 25 U.S. states and over 35 countries. She has studied and worked while living abroad in Spain, France, Brazil and Switzerland.