Homeowners insurance is often assumed to be a catch-all for anything that could go wrong with a house. It isn't — standard policies carry a specific, fairly consistent list of major exclusions, and several of them cover exactly the events most likely to cause serious financial damage.
Flood damage
This is the single most significant and most misunderstood exclusion. Standard homeowners policies almost universally exclude flood damage, regardless of the cause — heavy rain, storm surge, or overflowing waterways. Flood coverage requires a separate policy, commonly through the National Flood Insurance Program or a private flood insurer, and homes outside officially mapped flood zones can still flood.
Earthquake and earth movement
Earthquake damage, along with broader earth movement like landslides and sinkholes in many policies, is excluded by default and requires a separate endorsement or standalone policy — relevant well beyond the West Coast, given sinkhole activity in states like Florida.
Sewer backup and water damage from certain sources
Sudden, accidental water damage (like a burst pipe) is typically covered, but damage from sewer or drain backups is frequently excluded unless you've added a specific endorsement — a common and expensive gap for homes with older plumbing or basements.
Poor maintenance and gradual damage
Homeowners insurance covers sudden, accidental events, not gradual deterioration. Damage attributed to lack of maintenance — a slowly failing roof, long-term mold growth, or termite damage — is generally excluded, since insurers treat these as the homeowner's maintenance responsibility rather than a covered loss.
High-value items above sublimits
Standard personal property coverage often caps categories like jewelry, art, and collectibles at a low sublimit (sometimes $1,000–$2,500) regardless of your overall policy limit. Anything above that requires scheduling the item individually.
What to do about it
Review your policy's exclusions section directly rather than assuming, and price out flood coverage specifically even if you're not in a mapped flood zone — a significant share of flood claims come from outside officially designated high-risk areas.