How to Hire a Mold Company: 6-Step Checklist (2026)
Verify licensing, check certifications, spot red flags, compare quotes fairly. The 6-step hiring process that protects you from overpriced work and scams.
Finding mold in your home is stressful. Hiring the wrong company to fix it can make things worse. This guide walks you through how to find a qualified mold professional, what to verify before signing anything, and how to protect yourself from overpriced work and common scams.
In This Guide
- What to Look For in a Mold Professional: Licensing, insurance, certifications, reviews
- The Assessor vs. Remediator Distinction: Why this matters before you hire anyone
- Questions to Ask Before Hiring: What to ask on the first call
- Red Flags and Scams to Avoid: Warning signs that should make you walk away
- Understanding Certifications: What IICRC, ACAC, and NORMI credentials mean
- How Much Does Mold Remediation Cost?: Cost ranges and what drives the price
- How to Hire: Step by Step: The full process from start to finish
What to Look For in a Mold Professional
Not every mold company is the same. These are the credentials and qualities that separate legitimate professionals from contractors you should avoid.
State Licensing
Five jurisdictions run dedicated mold licensing programs: Florida, Texas, New York, Louisiana, and Washington DC. In Florida, Texas, New York and Washington DC, mold assessors and remediators must hold a state-issued license; Louisiana licenses mold remediation but not mold assessment. A few other states regulate mold work in other ways. Tennessee and Mississippi cover mold remediation under a contractor license classification, Connecticut's home improvement contractor registration covers it, and Virginia bars selling residential mold remediation without a certification from a nationally or internationally recognized certifying body. Most states have no mold license at all, and our 50-state mold licensing survey shows the rule, if any, in each state. Ask for the number and verify it yourself; do not take their word for it. The state databases are free and searchable, and each one is listed here with what a check can and cannot tell you.
Check that the license:
- Is active (not expired)
- Covers the right type of work (assessment vs. remediation)
- Has no disciplinary actions or complaints on record
Insurance
Every mold professional you hire should carry current insurance. At minimum, ask for:
- General liability: Covers property damage during work
- Workers' compensation: Required in most states if they have employees
- Professional liability (errors & omissions): Covers mistakes in assessment or remediation
Ask for a certificate of insurance (COI) and verify it's current before work starts. If they hesitate, that's a red flag.
Certifications
Certifications are separate from a state license, where your state has one. They document additional training or field experience in mold work. Industry certifications come from bodies such as the IICRC, ACAC and NORMI. See the certifications section below for a breakdown of what each means.
Reviews and Experience
Check Google reviews and the Better Business Bureau. Look specifically for:
- Recent reviews (within the last 12 months)
- Comments about how the company handled problems, not just praise
- Volume of reviews: five reviews is a thin track record
Ask how many mold projects they complete per year and whether they have experience with your specific situation (attic, crawl space, HVAC, post-flood, etc.).
The Assessor vs. Remediator Distinction
Before you start calling mold companies, understand this: mold assessment and mold remediation are two different jobs, and our recommendation is to have two different companies do them.
A mold assessor diagnoses the problem. They start with the building's water history, a visual inspection and moisture readings, add sampling only when it answers a defined question, document what they find, and create a remediation protocol, a written plan specifying what needs to be done. They do not remove mold.
A mold remediator fixes the problem. ANSI/IICRC S520-2024 has them inspect the site, make their own preliminary determination and write a work plan (§7.4, §7.5); where an independent assessor has written a protocol, the work plan carries it out. The work itself is containment, physical removal of the contamination (cleaning what can be restored and removing materials that can't), and drying.
When one company does both, they have a financial incentive to overstate the scope of your problem, whether or not they act on it. Seven jurisdictions put a rule on that conflict, from a ban on doing both on the same job in Texas, New York, Louisiana and Oklahoma to a 12-month restriction in Florida and a written disclosure in Maine and Washington DC. Elsewhere, state law allows it, and an independent assessment is our recommendation rather than a legal requirement.
For any job beyond a small patch, we recommend an independent assessment before hiring a remediator. The industry standard doesn't require one on every job: a remediator makes its own preliminary determination, and S520 says an independent assessment may not be needed when the scope can be determined without one (§1.2.1, §7.4). For a full breakdown of how this works, which jurisdictions have a rule on it, and why it matters, see our mold assessor vs. remediator guide.
If you're unsure whether you even need a professional, our DIY vs. professional mold removal guide can help you decide.
Questions to Ask Before Hiring
Ask these questions before you sign anything. A qualified professional will answer them without hesitation.
About credentials:
- What is your state license number, and what type of license do you hold?
- Can you provide a certificate of insurance for general liability and workers' comp?
- Do you hold any industry certifications (IICRC, ACAC, or NORMI)?
About the process:
- Do you perform both assessment and remediation? (If yes, that's a conflict of interest; see above.)
- Will you provide a written remediation protocol before work begins?
- Who checks the work at the end, and will anyone independent be involved?
About the project:
- How many projects like mine have you handled in the past year?
- What containment procedures do you use?
- What's your timeline, and what happens if you find more mold than expected?
About the contract:
- Is everything tied to the assessor's written protocol?
- What is the payment schedule? (Avoid paying in full upfront.)
- Do you provide a written warranty on your work?
For the complete list of questions organized by project phase, see our questions to ask a mold company guide.
Red Flags and Scams to Avoid
These are the warning signs that should make you pause or walk away entirely.
The "free inspection" offer. A company that offers a free inspection and then immediately quotes you for remediation has a direct financial incentive to find (and exaggerate) your mold problem. That doesn't mean the scope is inflated; it means the company pricing the remediation also decided how big it is. For anything beyond a small patch, our recommendation is an independent assessment from a separate company before you sign.
Refusal to provide license or insurance. Any licensed professional should hand over their license number and a COI without hesitation. Delays, excuses, or vague responses mean you should move on.
High-pressure tactics. A contractor who pushes you to sign the same day, claims the mold is spreading by the hour, or offers a discount only valid "right now" is using pressure to prevent you from doing your homework. Legitimate mold companies don't work this way.
Cash-only payment requests. This signals a company that may not be properly licensed or insured, and gives you no recourse if the work isn't done right.
Guaranteed mold elimination. Mold spores exist naturally in every home. Any company that guarantees to "eliminate all mold" or "make your home mold-free forever" is making a claim that's scientifically impossible. It's a sales tactic, not a promise they can keep.
For a detailed breakdown of how these scams work and how to protect yourself, see our mold remediation scams guide.
Understanding Certifications
If your state licenses mold work, its license is the minimum bar. Certifications from industry organizations document training and testing beyond it.
The Major Certification Bodies
IICRC: Institute of Inspection, Cleaning and Restoration Certification
The IICRC is a certification and standards body for the inspection, cleaning and restoration industries, and publishes the S520 Standard for Professional Mold Remediation.
- WRT (Water Damage Restoration Technician): Covers water damage and drying a structure, relevant to mold work
- AMRT (Applied Microbial Remediation Technician): A course-and-exam credential covering mold and sewage remediation; requires the WRT and has no field-experience prerequisite
- MRS (Mold Remediation Specialist): The IICRC's advanced, mold-only certification: no course, at least 12 months of verifiable mold remediation field experience, and an exam
ACAC: American Council for Accredited Certification
ACAC focuses specifically on indoor environmental quality and mold work.
- CMI (Council-certified Microbial Investigator): For assessors performing mold inspections, at 2+ years of verified field experience
- CMC (Council-certified Microbial Consultant): The same discipline at 8+ years
- CMR (Council-certified Microbial Remediator): For remediators, with the Council-certified Microbial Remediation Supervisor (CMRS) a tier above
- CIE (Council-certified Indoor Environmentalist): Broader indoor air quality credential
NORMI: National Organization of Remediators and Microbial Inspectors
- CMA (Certified Mold Assessor): Assessment-focused
- CMR (Certified Mold Remediator): Remediation-focused. Note that ACAC issues a CMR of its own with different requirements, so ask which body issued it
- MRSR (Mold-Related Services Remediator): NORMI's course and exam for Florida's mold remediator license of the same name. NORMI says they cover the training and examination Florida requires, after which the applicant applies to the state for licensure. The license itself is issued by Florida's DBPR, not by NORMI, so check it there
How to Weigh Certifications
Treat certifications as examples of relevant training, not a ranking. For remediators, look for credentials such as the IICRC's AMRT or MRS, ACAC's CMR or CMRS, or NORMI's CMR; for assessors, ACAC's CMI or CIE, NORMI's CMA, or a CIH for complex exposure questions. Most credentials belong to a person, not the company, so ask who on your job holds them. No single credential qualifies someone for the job, so look past the letters at the person: their training, their field experience with mold and moisture, and any license your state requires.
Always verify certifications directly through the issuing organization's website, not just from the contractor's claims.
For a complete breakdown of what each certification means and how to weigh them for your situation, see our mold certifications guide.
How Much Does Mold Remediation Cost?
Understanding costs helps you spot inflated quotes and budget realistically.
A typical mold remediation job costs $1,223 to $3,757, with an average of $2,369, from 7,952 project costs reported to HomeAdvisor. See our mold remediation cost guide for each kind of job. Cost drivers include:
- Size of the affected area: HomeAdvisor prints $10–$25 per square foot without saying how it was measured, and small jobs cost more per foot because containment and disposal don't shrink with them
- Location: Mold inside walls, in HVAC systems, or in crawl spaces costs more than surface mold
- Materials affected: Drywall and insulation removal adds cost; mold on concrete is often less
- Extent of containment needed: Larger containment zones take more time and materials
- Post-remediation verification: An independent check runs $200 to $600 on one Austin assessor's published price sheet. It isn't required on every job, and it's worth having on a large or complex one or where someone in the home has health concerns. Sampling is one way of doing it rather than a requirement: ANSI/IICRC S520-2024 §12 lists visual inspection, field data and odor detection alongside it, and its minimum completion criteria (a return to normal fungal ecology, dry materials, and a work area free of visible dirt, dust, debris, malodors and mold growth) don't call for sampling on their own.
Comparing prices is much easier with an independent assessment first. Without a written remediation protocol, quotes can describe different work; one contractor may be bidding on twice the scope of another.
Cost guides:
- National averages and cost factors: mold remediation cost guide
- What a mold inspection costs: mold inspection cost guide
The Right Way to Hire: Step by Step
Follow these steps to hire a mold professional without getting overcharged or under-protected.
Step 1: Get an Independent Assessment
For any job beyond a small patch, we recommend hiring a qualified mold assessor, licensed where your state requires it, who does not offer remediation services, before contacting any remediator. In our view it's the most important step. The assessor will inspect your home, document the problem, and create a remediation protocol, a written scope of work that specifies what needs to be done.
This protocol is what makes it possible to get comparable quotes from multiple remediators. Without it, each remediator scopes the job from its own walkthrough, which is legitimate, but the company selling the remediation is also the one describing the problem, and quotes built on different scopes are hard to compare.
See our assessor vs. remediator guide for a full explanation of this step and what a good assessment includes.
Step 2: Review the Remediation Protocol
Read the assessor's report carefully. It should document:
- Where the mold is located and how much area is affected
- Known or suspected moisture sources and the conditions contributing to them, and who is confirming and fixing them
- What materials need to be removed
- What containment and air filtration is required
- How completion will be checked after remediation, against what criteria, and whether an independent verification is recommended
If you don't understand something, ask the assessor to explain it before you start contacting remediators.
Step 3: Get Multiple Quotes from Separate Remediators
Share the protocol with at least two or three qualified mold remediators. Since they're all bidding on the same scope, you can compare prices directly. A quote that comes in significantly lower than the others may mean the contractor plans to cut corners. A quote that's significantly higher may mean they're adding work beyond what the protocol calls for. Ask why.
Step 4: Verify Credentials
Before selecting a contractor, confirm:
- License, where your state requires one, is active and covers the right work type
- COI (certificate of insurance) is current: general liability and workers' comp at minimum
- Any certifications claimed are verifiable through the issuing organization
Do not skip this step. Checking credentials is quick, and it is much easier to do before you sign than after.
Step 5: Check Reviews and References
Read Google reviews for the past year. Look for patterns, not just averages. Then ask the contractor for two or three references from recent mold projects, and actually call them. Ask whether the scope stayed consistent, whether the crew was professional, and whether they'd hire the company again.
Step 6: Get Everything in Writing
Your contract should include:
- Scope of work tied directly to the assessor's remediation protocol
- Specific materials to be removed
- Containment and air filtration procedures
- Payment schedule (avoid paying in full before work is complete)
- Timeline with milestones
- How completion will be checked and documented, and who does any independent verification
- What happens if additional mold is found during work
Do not allow work to begin without a signed contract.
When you're ready to compare options, you can browse verified mold remediation companies and see what we could verify for each pro before you call.
Frequently Asked Questions
How do I verify a mold contractor's license?
Should I hire the same company to assess and remediate mold?
What certifications should a mold professional have?
How many quotes should I get for mold remediation?
What are the biggest red flags when hiring a mold company?
How much does mold remediation cost?
This guide is for educational purposes only. Licensing requirements vary by state and change over time. Always verify current requirements with your state licensing board before hiring.