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FludZone

Flood Zone X Shaded vs Unshaded

Zone X has two subtypes that represent different levels of lower flood risk. Zone X shaded (formerly Zone B) is in the 500-year floodplain with a 0.2% annual chance of flooding. Zone X unshaded (formerly Zone C) is outside both the 100-year and 500-year floodplains and represents areas of minimal flood hazard.

Key Differences

Category
Zone X (Shaded)
Zone X (Unshaded)
Flood Risk Level
Moderate risk. 0.2% annual chance of flooding (500-year floodplain).
Minimal risk. Outside both the 100-year and 500-year floodplains.
Legacy Designation
Formerly called Zone B on older FEMA maps.
Formerly called Zone C on older FEMA maps.
SFHA Status
Not in the SFHA. No federal flood insurance mandate.
Not in the SFHA. No federal flood insurance mandate.
Insurance Requirement
Not federally required, but some lenders may require it.
Not federally required. Lenders rarely require it.
Insurance Cost
Preferred Risk Policy available: typically $400-$700/year.
Preferred Risk Policy available: typically $400-$600/year.
Map Appearance
Shown with gray or light shading on FEMA flood maps.
No shading on FEMA flood maps (blank/white area).

When This Difference Matters

The distinction matters most for risk awareness. While neither subtype carries a federal insurance mandate, Zone X shaded properties are statistically more likely to flood than unshaded properties. Homebuyers should recognize that Zone X shaded is still within a mapped floodplain (the 500-year), and about 25% of all NFIP claims come from properties outside the SFHA.

The Bottom Line

Both Zone X subtypes are lower-risk than SFHA zones, but Zone X shaded carries more risk than unshaded. Neither requires flood insurance by federal law, but voluntary coverage is affordable and recommended for both.

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Flood Zone X Shaded vs Unshaded FAQ

Is Zone X shaded in a floodplain?

Yes. Zone X shaded is in the 500-year floodplain, meaning it has a 0.2% annual chance of flooding. Over a 30-year mortgage, that translates to roughly a 6% chance of at least one flood event. Zone X unshaded is outside both the 100-year and 500-year floodplains.

Do I need flood insurance in Zone X shaded?

Federal law does not require it, but individual lenders may require coverage at their discretion, particularly for Zone X shaded properties. Given that about 25% of NFIP claims come from outside the SFHA and Preferred Risk Policies are relatively affordable, flood insurance is recommended.

Can Zone X become Zone AE?

Yes. When FEMA conducts new Flood Insurance Studies or updates flood models, areas previously mapped as Zone X can be reclassified as Zone AE or another SFHA zone. This can happen due to increased development, changes in drainage patterns, or improved flood modeling data.

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