The District of Columbia currently uses an annual assessment cycle. This means that all real property may be valued for property tax purposes annually. However, the city is divided into three groups that have approximately the same number of parcels and assessable base. One group of properties will be physically inspected each year. The other two-thirds will be valued via mass appraisal models.

Uniform and accurate assessments are the foundation of fair property taxation. In accordance with DC Code § 47-823(c), the Office of Tax and Revenue publishes a real property assessment/sales ratio study. This report measures assessment quality by looking at the most recent assessment program and comparing the results of that effort to actual market conditions.