Mold testing means collecting air, surface, or material samples and sending them to a lab. It is useful for specific questions, such as whether mold is hidden inside a wall or whether a cleanup worked. It is not needed for every mold problem: when you can see the mold, the EPA says sampling is usually unnecessary.
If you own your home and need mold testing, call the number on this page. We connect you with an independent local company that can take samples and explain the results.
When mold testing helps
- Hidden mold. A musty smell with no visible growth can point to mold inside walls, under flooring, or in the air conditioning system.
- Documentation. An insurance claim, a home sale, or a dispute with a landlord or contractor may call for lab results.
- Clearance after remediation. Testing confirms the work succeeded before walls are closed up.
- A second opinion. When a remediation quote seems large, independent testing can confirm the scope.
When mold is visible and the cause is clear, testing rarely changes the plan. The CDC says it is not necessary to identify the type of mold, because all molds are removed the same way.
Types of mold tests
| Test | What it shows | Limits |
|---|---|---|
| Air sample (spore trap) | Spore types and levels indoors, compared with an outdoor sample | A snapshot of one moment |
| Surface sample (tape or swab) | Whether a stain is mold, and which kind | Only the spot sampled |
| Bulk sample | Mold in a piece of drywall, carpet, or insulation | Requires removing material |
| Wall cavity air sample | Spores inside a wall, through a small hole | Indicates, but does not map, hidden growth |
| Dust DNA analysis (ERMI) | Estimates of mold types in settled dust | The EPA calls it a research tool not validated for routine use in homes |
Moisture readings are not a mold test, but they are often more useful than one: mold follows water. See how to test for mold.
How to read results
- Indoor versus outdoor. Indoor levels much higher than outdoor levels, or types found indoors but not outside, suggest an indoor source.
- Types, not only totals. Molds associated with water damage appearing indoors can point to a wet material.
- No pass or fail. There are no EPA or other federal limits for mold or mold spores, so results need interpretation in context.
A good testing company gives you the lab report itself, not just a summary, and explains what it means for your home.
What mold testing costs
- Individual lab tests: about $50 to $350 each, per HomeGuide
- Air test: about $250 to $350, and up to about $700 for extensive testing, per Angi
- Inspection with typical testing: about $300 to $1,000, national average near $670
See what a mold inspection costs.
Home test kits
Kits cost roughly $10 to $100. Settle plates grow mold in almost any home, because spores are present in all indoor and outdoor air. Swab kits can identify mold you can already see, which you rarely need to know. Neither can find hidden growth, measure the size of a problem, or find the moisture source.
Choosing a mold testing company
- Independence. A company that does not sell remediation has no stake in the result.
- Licensing. Florida and Texas license mold assessors. In both states, clearance after remediation is done by someone other than the remediation company.
- Method. Ask why each sample is needed, whether an outdoor comparison sample is included, and which accredited lab analyzes it.
- Price in writing. Ask what the base fee covers and what each extra sample costs.
Testing your home vs. testing your health
Testing the house shows what is in the house, not how it affects you. If you have symptoms, talk to a doctor. Medical groups do not recommend urine mycotoxin tests for assessing mold exposure. See mold exposure testing.
How our service works
When you call the number on this page, the call is free, and you are connected to an independent local company that serves your area. The company talks with you directly, can schedule testing, and gives you a price. There is no obligation to hire. We are not a testing company or contractor; check any company's license and insurance before you hire. Our service is for homeowners.
Find mold testing near you
Choose your state and city below for local conditions, typical costs, and licensing rules, or call the number on this page to be connected with a local company.