The state constitution requires that no more than two people from the same political party serve as commissioners. Johnson is not affiliated with a political party.
Governor Gary Herbert will nominate a new commissioner, whose appointment must be confirmed by the Utah State Senate.
In addition to his day-to-day responsibilities of ruling on a wide range of tax cases, Johnson was instrumental in the revision of the administrative rule that addresses the valuation of centrally assessed properties such as mines, railroads, utilities and telecommunications.
Johnson also supervised the Economic and Statistical unit, and is an acknowledged authority in valuation of centrally assessed and large commercial properties.
"Marc is a recognized expert in Utah tax laws," said Tax Commission Chair R. Bruce Johnson, no relation. "He has worked tirelessly over the years to ensure that those laws are fairly administered. His expertise, dedication and commitment to the public will be sorely missed."