Mold remediation companies by state

Mold work and the S520 standard

Mold remediation is removing mold growth from a building and its contents and cleaning the affected areas so they are back to a normal condition. It rarely stands alone. Mold follows moisture, so a good remediator also wants to know where the water came from and whether it has stopped. The water standard, S500, sends restorers to S520 wherever mold is found or suspected.

ANSI/IICRC S520, the Standard for Professional Mold Remediation, is the procedural standard for this work in homes, commercial buildings and institutions. When we checked iicrc.org in September 2026, the fourth edition (2024) was current. Its own list of components includes remediator qualifications, contents remediation, HVAC remediation and post-remediation verification.

Two roles in the IICRC vocabulary are easy to mix up. The remediator removes the growth. An indoor environmental professional (IEP) is someone trained to sample the building, send samples to a lab and interpret the results. For water jobs, S500 says many don't need an IEP and names the higher-risk situations where one should be brought in. On a mold job, ask whether an IEP is involved and which company is playing which role before you sign.

Reading a mold company's website

Our Evidence Score works from the company's own site plus third-party records. For mold, these are the items worth reading closely:

• A described process. Look for containment of the work area, removal of damaged porous materials, cleaning, and a check at the end. A page that only says "we kill mold" tells you nothing about how.
• How the job is signed off. S520 includes post-remediation verification. Ask who does it and what "done" means in writing.
• S520 named on the site. We record that as self-reported. The IICRC Certified Firm record is a separate check we haven't logged for any company yet.
• Whether they help with an insurance claim. What gets paid depends on your policy, so a company that explains what it documents is more useful than one that promises your insurer will pay.
• A warranty, and what it excludes if the moisture comes back.

Emergency items (a 24/7 line, a stated response time) matter less for mold than for a burst pipe, but they still count toward the score.

Using the state table

The table counts, for each state, the listed companies whose own website documents mold remediation. It is not a ranking. If your state licenses mold remediation, ask for the license number and check it with the state yourself. We only credit a license from the state's own record. New York's mold remediation licenses are checked automatically; elsewhere a mold license is usually unchecked. Follow a state link to see each company's Evidence Score, its coverage and the one-line reason it was listed.