Corey joined Aiken, St. Louis & Siljeg, P.S. as a shareholder, where he continued to manage complex trust, estate and guardianship matters, but also expanded his practice into business planning and succession, real estate transactions, creditor rights and commercial litigation. Corey also served as a court-appointed trustee and personal representative in complex and contentious cases.

Corey was a longstanding member of the Washington State Bar Association’s Real Property & Probate Section and Guardianship and Elder Law Section, as well the King County Bar Association’s Real Property & Probate Section and Elder Law Section. Corey served two terms on the executive committee of the King County Bar Association’s Elder Law Section.

In 2005, Corey was nominated and served as the chair of a committee with judges and court commissioners to draft forms to be used by guardians and trustees to report on their fiduciary activities. In 2012, Corey was nominated and served as co-chair of the Washington State Bar Association’s task force to revise the Uniform Durable Power of Attorney Act to reduce the financial exploitation of vulnerable and elderly persons.

After twelve years on the West Coast, Corey and his wife returned to Sioux Falls to be closer to their families. Upon returning to Sioux Falls, Corey served as an adjunct professor at a local university teaching employment law.

Corey joined Boyce Law Firm, LLP in 2013 and as a partner at the firm he focused on trust litigation representing fiduciaries, beneficiaries, and entities owned by trusts both nationally and internationally. He also continues a small estate planning practice and represents family members in guardianship and conservator proceedings. Corey is a frequent presenter at continuing legal education seminars for lawyers. Corey has been a presenter at over 50 seminars in Washington, California, South Dakota, Iowa, Ohio, Florida, Toronto and London. Corey has also been involved in legislative activities.

In 2020, Corey chased a long-held ambition to start his own business and opened Denevan Law Prof. LLC. In late 2022 and early 2023, Shannon and Meghann joined forces with Corey and Denevan Falon Joyce was born. Corey continues to focus on trust and estate litigation, administration and planning as well guardianships, conservatorships, and business litigation.