Black mold removal cost: $2,000 to $10,000 (HomeGuide 2026)

National figures. HomeGuide prices Stachybotrys jobs higher because they usually follow long water damage; HomeAdvisor and This Old House give one price for all molds.

Do this now: before you scrub or call anyone

Stop the water, size the patch, and keep it out of the air system; then decide who cleans it.

1. Find the water. The CDC says Stachybotrys needs constant moisture, so a leak, condensation or a wet floor is behind it. Fix the leak first or the mold comes back after cleaning.
2. Measure the patch. The EPA says most people can clean a moldy patch smaller than about 10 square feet, roughly 3 feet by 3 feet, themselves; above that, or after a lot of water damage, it points to its professional remediation guide.
3. Keep the HVAC off if the mold could be in it. The EPA says not to run a system you know or suspect is contaminated, because it can spread mold through the building.
4. Small patch on a hard surface: the EPA says to scrub it off with detergent and water and dry completely. The CDC says a bleach solution should be no more than 1 cup of bleach in a gallon of water, and never mixed with ammonia or other cleaners.
5. Do not paint over it. The EPA says paint applied over moldy surfaces is likely to peel.
6. Photograph it and call your insurer if the mold follows a sudden leak; the Texas Department of Insurance says mold on an item damaged by a covered loss is covered. Do not sign your claim over to a contractor.

Is black mold an emergency? Who should stay away

Mold is rarely a same-hour emergency, but a patch over 10 square feet, mold in the HVAC system, or someone in the house with asthma, a weak immune system or chronic lung disease moves it to a same-week call.

• Call this week: the patch is bigger than about 3 feet by 3 feet, it followed a flood or long leak, or it is inside a wall, under a floor or in a duct.
• Keep sensitive people out of the room: the CDC says people with asthma or mold allergies may have severe reactions, and immune-compromised people and people with chronic lung disease may get lung infections from mold.
• Water still coming in: that is a water mitigation call first; drying inside 24 to 48 hours is what stops more mold (EPA).
• Can wait: a small spot on bathroom grout or a window sill that scrubs off and stays off once the fan runs.

What is black mold, and is it more dangerous than other mold?

Black mold is Stachybotrys chartarum, and the CDC's answer on danger is that all molds should be treated the same: its fact page says "All molds should be treated the same with respect to potential health risks and removal" and "It is not necessary to determine what type of mold you may have growing in your home or other building."

• What it grows on: the CDC says material with a high cellulose content, such as fiberboard, gypsum board and paper, when there is moisture from water damage, leaks, condensation, water infiltration or flooding. "Constant moisture is required for its growth."
• What it looks like: greenish-black (CDC). Many other molds are also dark, and the CDC says the type does not change what you do: "if Stachybotrys chartarum or other molds are found in a building they should be removed."
• Health: the CDC says exposure to damp and moldy environments may cause a variety of health effects, or none at all; for some people a stuffy nose, sore throat, coughing or wheezing, burning eyes or a skin rash. It says no test exists that proves an association between Stachybotrys and particular symptoms, and that a suspected link to lung bleeding in infants has not been proven.
• "Toxic mold" quotes: HomeGuide prices Stachybotrys jobs at $2,000 to $10,000 against $500 to $4,000 for Aspergillus, and HomeAdvisor says black mold needs specialized handling. This Old House notes the EPA does not distinguish mold species in its cleanup advice. Ask any company quoting a premium for "toxic" mold what it will do differently and why.

How much does black mold removal cost?

Black mold removal costs $2,000 to $10,000 in HomeGuide's February 2026 guide, which prices Stachybotrys jobs separately. HomeAdvisor's June 2026 figure for mold remediation of any kind is $1,223 to $3,757 with a $2,368 average, and This Old House's March 2026 average is $2,300.

• Per square foot: $10 to $25 (HomeAdvisor; This Old House) or $15 to $30 (HomeGuide). HomeGuide's size bands: 10 to 100 square feet $500 to $1,500; 100 to 300 square feet $1,500 to $6,000; 300 to 1,000 square feet $6,000 to $15,000.
• Why Stachybotrys costs more: it grows on drywall and paper-faced materials after long water exposure, and This Old House says drywall that mold has penetrated generally must be removed and replaced. HomeGuide puts drywall replacement at $1.50 to $3.50 per square foot and painting at $1 to $3.
• Labor: HomeGuide lists $75 to $120 an hour and says labor is most of the bill; small to medium jobs take 1 to 3 days.
• Testing: the CDC does not recommend mold testing, and the EPA says sampling is unnecessary when mold is visible. If a company wants to test first, HomeAdvisor prices basic testing at $250 to $350; mold inspection covers when a test earns its fee.

City prices and local rules: Houston, Los Angeles, Denver and Boston.

Signs of mold in a house: smell, stains and where it hides

The first sign of mold is usually a musty smell, and the EPA says to suspect hidden mold when a building smells moldy but you cannot see the source. HomeGuide puts a mold inspection at $300 to $650 when the source is not obvious.

Causes from EPA and CDC guidance; prices from HomeAdvisor (Jun 2026).

A mold smell in the house with nothing visible is the case for a meter and a look behind things, not a spray. The EPA lists the back of drywall, wallpaper or paneling, inside walls around pipes, inside ductwork and above ceiling tiles as hiding spots.

Mold in walls, on ceilings and under sinks: what a company would check

A remediation company working to the IICRC S520 standard, now in its fourth edition, starts with an inspection and a preliminary determination of where the moisture came from, and ends with verification that the cleaning worked.

• Mold behind drywall: moisture readings through the paint, then a small cut to see the back of the board. The EPA says porous materials that have become moldy may have to be thrown away; This Old House says penetrated drywall comes out.
• Mold on a bathroom ceiling: whether the exhaust fan runs long enough and ducts outside. The EPA says to run the fan or open a window when showering and to keep indoor humidity below 60 percent, ideally 30 to 50.
• Mold under a sink: the leak, then whether the cabinet floor and the wall behind it are wet. A plumber fixes the leak; HomeGuide puts a leaking pipe repair at $150 to $850.
• Mold under carpet: the pad and subfloor. HomeGuide prices carpet at $2 to $8 per square foot and subfloor at $2.20 to $4.75.
• Containment: the EPA's commercial guide calls for no containment under 10 square feet, limited containment from 10 to 100, and full containment with professional judgment above 100 square feet. Ask what the quote includes.

Does homeowners insurance cover black mold removal?

Sometimes. The Texas Department of Insurance says mold that grows on an item damaged by a covered, sudden loss is covered, but most policies do not cover gradual leaks or seepage, including the mold that follows, and most do not include mold cleanup and testing after the damaged item is removed.

• Limits: NerdWallet reports insurers usually cap mold payouts at $1,000 to $10,000, with add-ons that raise the limit; check your declarations page.
• Before you file: the Texas Attorney General notes claims can show up in the CLUE database and affect future insurance, and that your insurer cannot require you to use a specific company.
• Paperwork: Filing a claim? Call your insurer as well as the restoration company, photograph everything before anything is moved, and do not sign an assignment of benefits or any contract that hands your claim to a contractor. Florida voids assignments on policies issued on or after January 1, 2023.

Black mold removal near me: licensing and what to ask

• Texas: mold assessors and remediators are licensed by TDLR and the same company may not assess and remediate the same project. Florida: jobs over 10 square feet need a DBPR-licensed assessor or remediator, and an assessor may not remediate a building it assessed within 12 months. Look the license up yourself.
• Experience and references: the EPA says to make sure the contractor has experience cleaning up mold and to check references.
• What is the moisture source, and who fixes it? Cleaning without the fix is money spent twice.
• What comes out, what gets cleaned, and how is it verified? Ask for the S520 steps in the written estimate.
• Will the HVAC be sealed or cleaned? If ducts are involved, see attic and duct mold.
• License number and proof of insurance. Check them before work starts.

Basement and crawl space jobs are on crawl space mold, the wider price picture on mold remediation cost, and drying after a leak on water damage restoration. Other trades: home repair costs. Calls go to an independent company that serves your area and takes this kind of job; hours vary. How calls work.