Flood zone X

Checked against FEMA and other official sources · Last reviewed October 8, 2026

What zone X means

On a FEMA Flood Insurance Rate Map, X is one of the "Non-Special Flood Hazard Areas." Those are the moderate- to low-risk zones that begin with B, C or X. The high-risk zones begin with A or V.

Zone X is defined against two benchmark floods:

• The base flood, also called the 100-year flood, has a 1% chance of happening in any year. Its reach marks the high-risk area.
• The 0.2-percent-annual-chance flood, often called the 500-year flood, has a 0.2% chance in any year.

Where your property sits relative to those two floods decides whether it is shaded or unshaded X. For more on the 1% flood, see what a 100-year flood means. [1][2]

Shaded X vs. unshaded X

Shaded X (moderate risk). FEMA describes these as "the areas between the limits of the base flood and the 0.2-percent-annual-chance (or 500-year) flood." In the example maps in FEMA's map-reading guide, moderate-risk X areas have orange shading. FloodSmart says these areas "may have reduced their risk with mitigation efforts such as levees, or experience shallow flooding, with water usually less than 1 foot deep or covering less than 1 square mile."

Unshaded X (minimal risk). These are areas outside the high-risk zone and higher than the elevation of the 0.2-percent-annual-chance flood. In that guide's example maps they are clear or unshaded. FloodSmart describes them as "at a lower risk of flooding, though not entirely without risk." [1][2][6]

Zones B and C

Some flood maps use letters B and C instead of shaded and unshaded X (more in flood zones B and C). The meaning is the same:

• Zone B = shaded X: moderate flood hazard.
• Zone C = unshaded X: minimal flood hazard.

Federal regulations list them together. One line reads "B, X Areas of moderate flood hazards," and another reads "C, X Area of minimal hazards." FloodSmart adds that zone C "may have ponding and local drainage problems that don't warrant a detailed study." [1][5][6]

Is flood insurance required in zone X?

Not by federal law. The federal mandatory purchase rule covers the A and V zones, not B, C or X. FloodSmart puts the rule this way: "You're required to have flood insurance if you own a home or business in a Special Flood Hazard Area (SFHA) and have a government-backed mortgage." FEMA says that outside those areas, in NFIP communities, flood insurance "is available, but not mandatory, for all property owners and renters," typically at a lower rate.

You may still have to buy it in two situations:

• Your lender requires it. FloodSmart says "some banks require flood insurance even if you don't live in a high-risk area." Check your loan documents or ask your lender.
• The property received federal disaster aid before. If so, you must have flood insurance to qualify for future disaster assistance, including FEMA grants and SBA disaster loans. FloodSmart says this requirement "is tied to a property, not an individual homeowner," so it can carry over to a buyer.

For a broader walkthrough, see do I need flood insurance?. [2][3][5]

The risk in zone X is real

FEMA's own claims data shows why it recommends coverage outside high-risk zones. FloodSmart states: "Over the past 10 years (2014 - 2024), nearly one-third of NFIP flood insurance claims (29%) came from areas located outside of current high-risk flood areas."

FloodSmart also notes that "most homeowners and renters insurance don't cover flood damage." A standard home policy usually won't pay for a flood, even in zone X. See does homeowners insurance cover water damage? and what flood insurance covers. [4]

What zone X means for your premium

Your zone no longer sets your NFIP price by itself. FEMA says the NFIP's current pricing approach "does not use flood zones to determine flood risk." It looks instead at factors such as flood frequency, several flood types (river overflow, storm surge, coastal erosion and heavy rainfall), "distance to a water source," and "property characteristics such as elevation and the cost to rebuild." Get a quote for your own building. See flood insurance cost. [7]

Your zone can change

FEMA and the NFIP update flood maps periodically. FloodSmart suggests checking yours every year. If an update moves your property from X into a high-risk zone, you may then be required to carry flood insurance if you have a government-backed mortgage.

FloodSmart says buildings newly mapped into a Special Flood Hazard Area may qualify for a "Newly Mapped" discount. You must buy or renew a policy within the first 12 months after the map update. After that, the rate rises by no more than 18% a year until it reaches the full-risk rate. To look up your current zone, see what flood zone am I in?. [6]

Questions people ask