Glossary

Mold exclusion

Policy wording that removes or caps coverage for mold, fungus and wet rot, usually leaving a small limit for growth that follows a covered water loss.

Also called: fungi exclusion, mold fungus and wet rot exclusion, limited fungi coverage

The mold exclusion is policy language that removes or limits coverage for mold, fungus, wet rot and similar growth. Insurers tightened their wording after a wave of costly mold claims in the early 2000s, and the result varies by company. Many policies, including some built on ISO forms, exclude mold and then give a limited amount back for growth that follows a covered water loss.

ISO's limited fungi endorsement, HO 04 27, is built around a $10,000 first-party limit for the policy year, with higher options, and other insurers choose their own figures. Say a covered pipe burst soaks a wall and mold spreads before it dries (hypothetical). The water damage is paid under the normal limits, but the mold cleanup is paid only up to the fungi limit, and testing and tear-out can use up that limit quickly.

If the underlying cause is excluded, such as flood or a long-running leak, the mold is generally not covered at all. Insurers can also argue that slow drying or delayed reporting let mold grow, so dry the structure fast and call in the claim. Find your fungi limit on the declarations page or in the endorsements. The guide does homeowners insurance cover mold? explains how adjusters handle it, and sudden vs gradual water damage: where insurers draw the line covers the leak side.

Last reviewed October 10, 2026

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Related terms

Exclusion A policy provision that removes coverage for a stated cause, type of loss, property or circumstance that the coverage would otherwise reach. Sublimit A cap on payment for one type of loss or coverage that is lower than the main policy limit, such as a set dollar amount for mold or sewer backup. Gradual damage Harm that builds up over weeks, months or years, such as a slow leak, rot or corrosion, which most homeowners policies exclude. Sudden and accidental Wording insurers use to separate covered, abrupt losses such as a burst pipe from slow, foreseeable damage like a leak that has dripped for months. Water backup coverage An optional add-on that pays for damage when water or sewage comes up through drains or sewers, or when a sump pump fails or overflows.

Related guides

Claims for hidden damage discovered later Can you claim damage found months after a storm, leak or fire? What decides it: cause, timing, late-notice rules, deadlines that run from the loss, and proof. Does homeowners insurance cover mold? Mold is covered only when a covered water loss causes it, and often under a low sublimit. What the ISO HO-3 says, which caps apply and how to protect a claim. Sudden vs gradual water damage: where insurers draw the line Why a burst pipe is usually covered and a months-long drip often is not, what the 14-day seepage clause says, and how timing evidence decides slow-leak claims. Termites, pests, wear and tear: the maintenance exclusions Policies treat termites, rodents, rot and aging as maintenance. What the HO-3 excludes, and the resulting damage that can still be covered.