A typical program takes two years to complete, with adjusted tax bills coming out the year after completion. Generally as a result of revaluation, some shares of taxes will go up, some will go down, and some will stay the same. The differences are caused by economic trends that vary from neighborhood to neighborhood, and vary also among classes of property.
The new values simply establish equalization; many other facts of assessment procedures determine the final tax bills. In Ohio, by law, assessed valuations are determined by taking 35% of the market value appraisals; then local tax rates are applied to reach each tax bill. Typically, many of these rates are adjusted after a revaluation to prevent a community-wide inflation of values from causing a large-scale inflation in tax bills.