Zones B and C are FEMA's older names for lower-risk areas. Here is what they mean today. Paste an address below to see its FEMA flood zone, or a whole list to check them all at once.
Quick answer
Flood zone C is an older FEMA name for areas of minimal flood risk, above the 0.2% annual chance ("500-year") flood level; on newer maps it is unshaded zone X. Zone B is the older name for moderate risk, between the 100-year and 500-year floodplains, now shaded zone X. Neither is a high-risk zone, so flood insurance isn't required by federal law, though it's available.
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US addresses with a house number and a state or ZIP. Only the address is used for the check.
FEMA replaced zones B and C with shaded and unshaded zone X in the mid-1980s, and maps are updated community by community, so some older flood maps still use the old letters. They mean the same risk as shaded and unshaded X.
Flood insurance isn't required by federal law outside the high-risk A and V zones, though a lender can ask for it. It is usually cheaper here than in high-risk zones, and FEMA says more than 20% of flood insurance claims come from outside them.
A guide and a planning check, not an official flood zone determination: a lender's determination, or FEMA's own map, is the official answer for a single property.
What does flood zone C mean?
Minimal flood risk: above the 500-year flood level. On newer FEMA maps it's called unshaded zone X.
What does flood zone B mean?
Moderate flood risk: between the 100-year and 500-year floodplains. On newer maps it's shaded zone X.
Do I need flood insurance in zone C?
Not by federal law, though a lender can ask for it. Policies are available and usually cost less than in high-risk zones.