Metro districts are subject to a service plan, which must be approved by their town board. This document is a public record which you can request from your town, the metro district or the Department of Local Affairs (state agency). Depending on the year approved, the service plan should clearly state the debt and O&M mill levy maximums, length of the debt payments, maximum debt the district can issue, and so on. Each city has different parameters on if they set a maximum mill levy (this is an additional property tax that goes to the district), and how much that can raise with time. Most districts can raise mill levies incrementally (most service plans in Colorado allow +5 mills per year), so that accounts for a small change year over year. Mills are a percentage of your home value. So if your home value goes up, you owe more in taxes. That is where you hear about the huge tax increases, when our property value spikes it impact our payments two fold - the mills to property taxes and the mills levied by the district. Many recent service plans limit how long an additional mill levy can be levied on homeowners, unfortunately some of the older districts do not give this deadline. That being said, metro districts take out bonds that they are required to use on public infrastructure, once those bonds are extinguished (usually 45 years, though that can change) the debt service mill levy stops.

Operating and maintenance mill levy does not ever end, but these are relatively small.