business planning attorney Adam Oster


My practice at Legacy Law Firm focuses exclusively on business and estate planning, probates and estates, trust administration and guardianship and conservatorships.   I enjoy helping entrepreneurs and business owners with business formation and transactions.  Whether it’s an entrepreneur with a new idea or a life-long business looking at business succession planning, I strive to be a valuable part of ensuring those business dreams become reality.

I like taking a proactive approach and holistic mindset when helping clients.  Business planning, tax planning, and estate planning are intertwined.  It’s critical that those areas aren’t looked at and planned for in silos or opportunities are going to be missed and problems occur.  Advising clients from a private wealth and entrepreneurial mindset helps ensure maximum results.  Being part of a team that is able to provide entrepreneurs and business owners with this holistic approach is exciting for me.  Likewise, this approach makes me understand that it’s not about just getting something in place, it’s about asset protection planning and keeping things a well-oiled machine as well.  Helping people and businesses keep climbing that ladder and improving has a lasting impact on that individual, their loved ones, and the community.  That’s a legacy I want to help people achieve and leave.

Prior to joining Legacy Law Firm, P.C., I worked at Tallgrass Wealth Management where I assisted with retirement planning, tax planning and yearly tax return preparation.  I grew up in Avon, South Dakota.  I graduated from South Dakota State University with a Bachelor of Art in Economics.  I then moved to Nebraska for law school and graduated from the University of Nebraska School of Law in 2016.  I’m an avid golfer and enjoy recreational sports and reading.

Unique facts:

  • Who do I admire most?  I admire my parents the most for the core values they have taught me.  They have given me the foundation for a successful future.
  • Little known fact about me?  I have previously been a taxi driver
  • My personal interests include all things related to my favorite sports teams, traveling and cooking!

Some of my favorites are:

  • Food – Surf n Turf
  • Movie – Shawshank Redemption
  • Book – Tiger Woods by Jeff Benedict and Armen Keteyian
  • Song – For Those About to Rock – AC/DC and many others
  • Place – First tee of ANY golf course

Areas of Practice

  • Business Organizations & Transactions
  • Business Succession Planning
  • Estate Planning, Wills, Trusts & Asset Protection Planning
  • Probate, Estate & Trust Administration

Bar Admissions

  • South Dakota
  • Nebraska


  • University of Nebraska School of Law (J.D.)
  • South Dakota State University, Bachelor of Art in Economics


  • South Dakota Bar Association