Guides
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.
Homeowners insurance covers mold only when a covered event causes it, and even then the payment is often capped. Mold that follows a burst pipe or a failed water heater is commonly covered, up to a mold sublimit if your policy has one. Mold that grows from humidity, a slow drip nobody fixed, groundwater or a sewer backup usually is not.
This guide describes the ISO HO-3 (form HO 00 03 05 11) because most company forms are built from it. Your insurer's own form, its mold endorsement and your state's amendatory endorsements control, so read the declarations page and the endorsement list before you rely on anything below.
What the standard HO-3 says about mold
The HO-3 does not treat mold as a cause of loss in its own right. It handles mold in the list of things the policy does not insure under Coverage A (dwelling) and Coverage B (other structures): "mold, fungus or wet rot." Then it gives some back: the policy does insure loss caused by mold, fungus or wet rot that is hidden within walls or ceilings, beneath floors or above ceilings, if the loss results from the accidental discharge or overflow of water or steam from one of these sources:
- A plumbing, heating, air conditioning or automatic fire sprinkler system, or a household appliance, on your property.
- A storm drain, or water, steam or sewer pipes, off your property.
For this purpose the form says a plumbing system or appliance does not include a sump, sump pump or related equipment, or a roof drain, gutter or downspout. The same rule appears in the Coverage C (personal property) peril for accidental discharge, which excludes loss "caused by mold, fungus or wet rot unless hidden" in the same places. That language comes from the ISO form, which you can read at the Maine Bureau of Insurance's copy of HO 00 03 05 11.
Three things follow from that wording.
The water has to be covered first. Mold after a supply line bursts inside a wall is within the carve-back. Mold after a rain leak, a clogged gutter, a window that never sealed or water seeping up through a slab is not, because none of those is a discharge from a plumbing system or appliance. The roof leak itself may be covered; the mold that follows is the part insurers decline. See is a roof leak covered by homeowners insurance?.
The word "hidden" does real work. Mold you can see growing on a bathroom ceiling may not count as "hidden" even if the water came from a covered source, and adjusters differ on mold discovered only after a wall is opened. If this is your situation, ask for the insurer's position in writing.
Slow leaks are a separate fight. Many company forms add wording about long-term seepage or leakage. A hidden leak that ran for months can produce a covered water claim under one form and a denial under another. sudden vs gradual water damage: where insurers draw the line explains where insurers draw that line.
The mold sublimit and limited-coverage endorsements
Many insurers replace the ISO carve-back with their own limited-mold or "fungi, wet or dry rot, or bacteria" endorsement. These are usually written as a sublimit: a fixed annual dollar amount that sits inside, not on top of, your Coverage A and C limits. The amount appears in the endorsement or on the declarations page, and it differs by insurer, by state and by the option you chose when you bought the policy.
ISO introduced optional limited-mold endorsements for its homeowners program in 2002, and Vermont's insurance division approved them for use there effective November 1, 2002. Its filing guidelines for companies that wrote their own versions are a useful example of how a regulator framed the cap. They required a minimum $10,000 aggregate property sublimit and a minimum $50,000 aggregate liability sublimit, said the property sublimit may include damage to property, removal cost, the cost of tearing out and replacing property to reach the mold, and testing, and said mold following fire or lightning should stay covered without the sublimit (Vermont Insurance Division, Mold Limitation / Exclusion Filing Guidelines). Those are Vermont's rules, not a national standard. Other states set their own, and some set none. The practical point is the shape of the typical endorsement: one annual cap that has to cover testing, tear-out, removal and rebuilding together.
Texas offers a second example of a state that treats mold specifically. The Texas Attorney General says that most homeowners policies sold in Texas are HO-A policies, that these generally cover only sudden and accidental water leaks, that many do not cover mold remediation, and that those that do generally cap it (Texas Attorney General, Mold Remediation). See Texas for the state's rules and home insurance rules by state for others.
A worked example makes the cap concrete. This is hypothetical.
Say a supply line fails inside a bathroom wall. Water damage to drywall, flooring and cabinets comes to $14,000. Mold remediation, including opening the wall, containment, air scrubbing and rebuilding, comes to $18,000. Your deductible is $2,500 and the policy has a $10,000 mold sublimit. The insurer pays the $14,000 water loss, pays mold up to $10,000, and applies the deductible once. You are left with the $8,000 of mold cost above the cap, plus the deductible.
If the same mold cost were only $6,000, the sublimit would never come into play. It bites when the problem is found late.
Common situations and likely outcomes
| Situation | Likely result under a typical HO-3 | Why |
|---|---|---|
| Burst or leaking supply line inside a wall, mold found behind the drywall | Covered, often subject to a mold sublimit | Hidden mold from accidental discharge from plumbing |
| Visible mold from a bathroom fan that never worked | Not covered | Maintenance, wear and tear, not a covered discharge |
| Mold after a roof leak | Water damage may be covered; the mold usually is not | Roof leaks are not a plumbing or appliance discharge |
| Mold after a sewer or sump backup | Not covered unless you bought a water backup endorsement and it addresses mold | Backup and sump overflow are excluded water; see water backup and sewer backup coverage |
| Mold after a house fire or lightning strike | Often covered as part of the fire loss | Some endorsements and state rules, Vermont's among them, keep mold after fire or lightning outside the sublimit; check yours |
| Mold after a flood | Check the NFIP policy, which has its own rules | Homeowners policies exclude flood |
| Mold in a damp crawl space or basement with no covered water event | Not covered | Seepage, groundwater and condensation are not covered perils |
On the flood row, the NFIP dwelling form excludes water, moisture, mildew or mold damage that results primarily from a condition substantially confined to the dwelling or within the owner's control, including failure to inspect and maintain the property after a flood recedes (44 CFR Part 61, Appendix A(1), Art. V.D.4%20to%20Part%2061)). That makes drying fast after a flood a coverage issue as well as a health one.
Why timing decides the claim
Mold claims turn on what happened in the first two days. The EPA says to dry water-damaged areas and items within 24 to 48 hours to prevent mold growth (EPA, A Brief Guide to Mold, Moisture and Your Home). The policy also puts that duty on you: under "Duties After Loss" you must protect the property from further damage, and the neglect exclusion removes coverage for loss resulting from failing to use all reasonable means to save and preserve property at and after a loss. An insurer that sees a wet carpet left a week before a claim was reported has a ready argument that the mold was your delay, not the pipe. reasonable repairs: what you can fix before the adjuster comes explains how emergency drying is treated as part of the claim, and duties after loss defines the obligation.
What to do when you find mold
- Stop the water and report the claim. Shut off the source, then call the claims line. Do not wait to see whether the mold "comes back." Ask for the claim number.
- Photograph before you touch anything. Capture the source, the affected materials and any moisture readings. Keep a sample of removed material if the adjuster has not yet inspected. documenting damage: photos, video and receipts covers what to capture.
- Dry the area and keep the equipment log. Extraction, air movers and dehumidifiers within the 24 to 48 hour window protect both the house and the claim. Get an itemized invoice. See water mitigation companies and your claim.
- Ask the adjuster three questions in writing. Does the policy have a mold endorsement or sublimit? What is its amount? Does it include testing and tear-out? The answers decide how much you can spend before you reach the cap.
- Keep assessment and remediation separate where you can. Some states license mold assessors and remediators and bar one license holder from doing both on the same project. Texas does (Tex. Occ. Code 1958.155), and it also has the remediator provide a certificate of mold remediation (1958.154). An insurer there may not make an underwriting decision based on previous mold damage or a mold claim if the property was remediated, as shown by that certificate, or an independent assessor or adjuster found no evidence of mold (Tex. Ins. Code 544.303). Check your own state before signing a single contract that covers both testing and removal.
- Hold the permanent rebuild until the scope is agreed. Do not close the wall until the adjuster has had a chance to inspect what is behind it.
Testing is not the first step
The CDC does not recommend mold testing, noting that there are no set standards for an acceptable quantity of mold in a home and that sampling cannot show who will become sick (CDC, About Mold and Your Health). The EPA agrees that if visible mold growth is present, sampling is usually unnecessary, and says the cause of the moisture must be found and fixed. Spend the first dollar on stopping the moisture, not on a lab report. Clearance testing after remediation can be what a buyer, a lender or a state certificate requires, and some policies count testing toward the capped mold amount. Ask first.
How a mold claim can follow you
Claims for mold and water damage are recorded in the claims database insurers use. The Texas Attorney General warns that some homeowners who filed such claims later had trouble renewing or buying coverage, and that insurers have in some cases reported inquiries about a mold claim even when no claim was made (Texas Attorney General). The Texas Attorney General adds that you do not have to report mold to your insurer if you pay for the remediation yourself, though a policy may still require prompt notice of the water damage. See CLUE reports: how claims history follows you and your house and the home insurance claim checklist.
Key takeaways
- The ISO HO-3 excludes mold but gives back loss from hidden mold caused by accidental discharge from plumbing, heating, air conditioning, sprinkler systems or household appliances.
- Many policies cap mold at a sublimit that covers testing, tear-out, removal and rebuild together; find the amount on your declarations page or endorsements.
- Mold from a roof leak, humidity, groundwater, sewer or sump backup, or neglected maintenance is usually not covered.
- Dry water damage within 24 to 48 hours and report quickly; delay hands the insurer the neglect and failure-to-mitigate arguments.
- Ask your insurer in writing about the mold sublimit and what it includes before you sign a remediation contract.