Mr. Severson's career in both private and public practice has focused on state and local government tax and finance. His litigation experience includes complex tax valuation disputes, class actions challenging state and local taxes and fees, valuation and equalization of public utility property, excise tax litigation, commerce clause limitations on state tax authority, taxation of leasehold estates and other partial interests in publicly-owned property, challenges to special levy tax authority, governmental financial management practices and procedures, inter-governmental tax immunity and the statutory authority of local governments and tax officials. Mr. Severson has considerable experience in municipal and administrative law, general litigation and appellate practice.

After a brief stint in Washington D.C. following law school, he began his practice in Washington state as a deputy prosecuting attorney for King County, where he advised and represented county officials on tax and finance matters. He is a member of the bars of Washington state, the U. S. District Court for the Western District of Washington and the U.S. Court of Appeals, Ninth Circuit.