In addition to the areas described in the previous section, the following zone designations also exist:
| Zone | Description |
| SHX (Shaded X) | Areas where there is a 0.2 percent chance of a flood in any given year (also known as a 500-year flood zone). FIRMs designated these as X zones, but have shading. |
| None | Areas for which there is no available FEMA flood zone. |