Only when it grows out of a sudden covered event such as a burst supply line or a storm-damaged roof, and then commonly only up to a capped endorsement of $5,000 to $10,000; mold from a slow leak, from humidity, from deferred maintenance or from flooding is excluded on nearly every policy.
Mold is not a peril. It is a consequence, and the policy asks what caused it. That single question decides almost every mold claim: water that arrived suddenly and accidentally is covered, water that had been arriving for months is not, and the remediation bill follows the water rather than the spores.
General information, not insurance advice. Your own declarations page and the fungi endorsement on it are what actually control the answer for your house.
Sudden and accidental is the whole test
A washing machine hose that lets go on a Tuesday, a water heater that splits, a supply line under a sink, a pipe that freezes and bursts, or a roof opened by wind are covered causes of loss on a standard policy. If mold grows in the wall behind one of those, the mold is treated as part of that claim, subject to whatever the policy's fungi limit is.
A shower pan that has been leaking into the subfloor for two years, a swamp cooler that drips all summer, condensation on a poorly ventilated bathroom, or a roof that has been letting water in since before you bought the house are all maintenance, and maintenance is excluded. Carriers word this as continuous or repeated seepage over a period of weeks or more, and it is the exclusion that ends most mold claims.
Flood is its own case. Mold after flooding is not covered by a homeowners policy at all, because the flood was not covered either; that is a National Flood Insurance Program claim if there is a flood policy in place.
The cap, and where to find it
Most policies written today carry a limited fungi, wet rot and bacteria endorsement rather than open-ended mold coverage. The limit is commonly $5,000 to $10,000 and covers testing, remediation and the tear-out and rebuild needed to reach the growth. Higher limits can usually be bought for a modest premium, and on an older home with original plumbing that is a reasonable thing to buy.
Read the endorsement, not the brochure. It will say whether the limit is per occurrence or per policy period, whether it is inside or on top of the dwelling limit, and whether it applies to liability claims from a tenant or a guest as well as to your own property.
How a mold claim actually goes
Report it the day you find the water, not the day you find the mold. Delay is the second most common reason a mold claim is denied, because the policy requires prompt notice and because a slow response converts a sudden loss into a continuous one. Stop the water, photograph everything before anything is torn out, keep the failed part, and keep receipts for the emergency dry-out.
The adjuster will want to establish the date and cause of the water. A plumber's invoice describing a failed fitting is worth more than any amount of argument about the mold itself. If the claim is denied, the Nevada Division of Insurance takes consumer complaints about how a carrier handled it, and the policy's appraisal clause is the route for a dispute about the amount rather than the coverage.
In Las Vegas the water is usually indoors
Valley humidity is low enough that ambient mold is rare, which means nearly every case here starts with a plumbing failure, an air conditioning condensate line, a water heater, or an irrigation line against the foundation. Homes built with polybutylene supply piping, common in some valley neighborhoods built in the 1980s and early 1990s, carry more of this risk than the age of the house alone suggests.
Two practical points at purchase. A Nevada seller must disclose known defects on the seller real property disclosure form, and previous water intrusion is exactly that; and an inspector will flag staining and moisture but is not a mold assessor, so a specific test is a separate hire when the report raises it.
Questions people ask
Does homeowners insurance cover black mold specifically?
The color and species do not change the answer. Coverage turns on what caused the water, and the same limited fungi endorsement applies whether the growth is black, green or white.
Will insurance pay for mold testing?
Usually only as part of a covered claim, and inside the fungi limit rather than on top of it. Testing ordered on your own to satisfy curiosity or to support a sale is normally an out-of-pocket cost.
Does a home warranty cover mold?
No. A warranty covers systems and appliances failing from wear, so it may pay to repair the pipe that leaked, but remediation of the resulting mold is outside every standard service contract.