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Mold Assessor vs. Mold Remediator in Texas: Why They Must Be Separate

Independent consumer guide. Not affiliated with TDLR. Primary sources: Occupations Code Chapter 1958, the TDLR Mold Assessors and Remediators program, and the TDLR mold FAQ.

MAC/ACO vs. MRC/RCO: Assessment Licenses and Remediation Licenses

Texas Occupations Code Chapter 1958, administered by the Texas Department of Licensing and Regulation (TDLR), splits mold work into two licensed tracks. Mold assessment means inspecting or surveying a structure for mold, developing a mold management plan or remediation protocol, or collecting or analyzing a mold sample (§1958.001(5)). Mold remediation means removing, cleaning, sanitizing, demolishing, or otherwise treating mold or mold-contaminated matter that was not purposely grown there (§1958.001(6)).

In practice you will see these TDLR prefixes on license numbers. Match the prefix to the job, then look up both the individual and the company:

Related credentials include Mold Assessment Technicians (MAT), who support assessment work, and registered Mold Remediation Workers (MRW), who work under a licensed remediation contractor. Those credentials do not replace a MAC for protocol and clearance or an MRC/RCO for running a regulated remediation job. License types are listed on the TDLR mold program home page.

Why Texas Requires Separation: Occupations Code §1958.155

The conflict-of-interest rule is short and strict. Under §1958.155:

• A license holder may not perform both mold assessment and mold remediation on the same project.
• A person may not own an interest in both the entity that performs assessment and the entity that performs remediation on the same project.
• License holders that are not individuals must disclose ownership interests to TDLR and report ownership changes.
• The section does not apply to a license holder employed by a school district working on a project for that school district.

That structure exists so the party who defines the scope and later evaluates clearance is not the same party who profits from the removal work. The Texas Attorney General's mold consumer page similarly warns people to be wary of companies that push multiple services in ways that skip independent judgment. For homeowners, the practical rule is simple: two independent licensed firms on a regulated job—one for assessment, one for remediation.

How a Compliant Assessor + Remediator Project Runs

Chapter 1958 sequences the work so assessment and remediation stay distinct from first protocol through closeout:

1. 1

   Independent assessment first

   A licensed assessor (MAC/ACO) inspects, may sample, and delivers a written work analysis listing rooms or areas, quantities of material, proposed methods, and clearance criteria before remediation begins (§1958.151).

2. 2

   Separate remediator’s work plan

   A different licensed remediator (MRC/RCO) gives you a written work plan that follows the protocol, and keeps a copy on site (§1958.152).

3. 3

   TDLR project notice

   The remediator notifies TDLR at least five days before starting, or by the next business day in a water-damage emergency that would increase mold contamination if delayed (§1958.153).

4. 4

   Remediation, then independent clearance

   The remediator performs the work. The assessor evaluates clearance against the protocol. Under §1958.154, the CMDR must include the assessment license holder’s statement that the mold was remediated as outlined in the plan.

5. 5

   Closeout documents

   Within 10 days of completion you should receive before-and-after photos (§1958.156) and the Certificate of Mold Remediation (§1958.154). Keep them for insurance and, if you sell within five years, for the buyer (§1958.154(b)).

Licensees must also give the client and property owner TDLR's Consumer Mold Information Sheet before mold-related activity begins (TDLR FAQ). For the broader licensing picture, including the 25 contiguous square-foot threshold and owner exemptions, see our Texas mold laws guide.

The CMDR: Why Clearance Comes From an Assessment License Holder

The Certificate of Mold Damage Remediation (often called the CMDR; Texas Department of Insurance form MDR-1) is where the separation rule shows up on paper. Under §1958.154, not later than the 10th day after a license holder completes mold remediation, that remediator must provide a certificate to the property owner. The certificate must include a statement by a mold assessment license holder that, based on visual, procedural, and analytical evaluation, the mold contamination identified for the project has been remediated as outlined in the mold management plan or remediation protocol. If the assessment license holder determines the underlying cause was remediated so it is reasonably certain mold will not return from that cause, the certificate says so—language that matters for insurance underwriting rules elsewhere in Texas law.

In other words, the remediator delivers the form, but an assessment licensee—not the party who did the remediation—provides the evaluation statement required by §1958.154. That is another reason a “one-stop” company doing both roles on the same project conflicts with how Texas designed the paperwork.

How to Verify Both the Assessor and the Remediator

Start with the assessor. Get a written protocol from a licensed MAC/ACO before remediation begins, then solicit bids from independent MRC/RCO firms that will follow that protocol—not rewrite the scope to inflate work. When you compare remediator bids, keep the assessor's clearance criteria in mind so you are not paying for removal that will fail the post-remediation evaluation.

Always confirm licenses on the official free TDLR License Search (or the License Search form). Our step-by-step TDLR verification guide covers prefixes, digit-only search, and company vs. individual lookups. For this conflict rule, do at least the following:

• Get written license numbers for the assessor individual (MAC), assessment company (ACO if used), remediator individual (MRC), and remediation company (RCO if used).
• Search each one. Confirm the license type fits the role, names match the contract, and expiration dates cover the project.
• Confirm you have two separate firms for assessment and remediation on this project, and ask both whether any person owns an interest in both entities for this job (§1958.155(b)).
• If a search returns nothing, remember License Search lists active licenses only. Call TDLR Customer Service at 800-803-9202 before you sign. Report suspected problems through TDLR complaints.

Red Flags: Same Company Doing Both When It Is Not Allowed

Use these warning signs before you pay a deposit or authorize containment. They do not prove a violation by themselves, but they mean you should pause and verify:

• One company offers to “inspect, remove, and clear” the mold on the same project without an independent assessor.
• The assessor and remediator share the same owners, brand, or “partner” arrangement that looks like common ownership on one job (§1958.155(b)).
• Only a remediation license is offered for sampling, protocol writing, or final clearance.
• Only a worker registration (MRW) is presented for a job that needs a remediation contractor and company.
• No written work analysis from an assessor before remediation starts (§1958.151), or no remediator work plan on site (§1958.152).
• They refuse to put TDLR license numbers on the estimate or contract, or the names on TDLR do not match the paperwork.
• They claim SB 1255 somehow lets one firm do both roles, or they invent a new “under-10” rule as if SB 1255 created it.

Small projects under 25 contiguous square feet and certain owner exemptions can change who needs a license at all—but they do not rewrite §1958.155 for a licensed firm you hire to perform a regulated project. If you hire a licensed remediator for a small area, TDLR's FAQ still expects that remediator to follow the rules that apply to license holders, including working from a protocol prepared by a licensed mold assessment consultant. When in doubt, read the statute and call TDLR.

Also watch for “referral partnerships” that blur ownership. §1958.155(b) bars a person from owning an interest in both the assessment entity and the remediation entity on the same project. A friendly referral between truly independent firms can be fine; shared ownership, shared control, or a single company wearing both hats on one job is the problem the statute targets.

SB 1255 Did Not Create the Under-10-Units Rule

Homeowners sometimes hear confused marketing about Senate Bill 1255. Get the citation right. SB 1255 (89th Legislature), effective September 1, 2025, amended Chapter 1958 and repealed §1958.102(b)—the former exemption for employees working under the supervision of a mold assessment or remediation license holder. That is the supervised-employee change.

The exemption for an owner (or the owner's managing agent or employee) performing mold assessment or remediation on a residential property the owner owns with fewer than 10 dwelling units is §1958.102(e). That subsection predates SB 1255. Do not say SB 1255 created the under-10 rule. The under-10 exemption also does not apply if the managing agent or employee engages in mold assessment or remediation for the public. For more on exemptions and the 25 sq ft remediation threshold, see Texas mold laws.

Frequently Asked Questions

Primary Sources

• Texas Occupations Code Chapter 1958 (§1958.154, §1958.155, §1958.102)
• TDLR Mold Assessors and Remediators and TDLR mold FAQ
• TDLR License Search
• TDLR Mold Remediation Consumer Protection sheet (2025, PDF)
• SB 1255 (89R) bill history
• Texas Attorney General: Mold Remediation

This page is general information for Texas property owners, not legal advice. Statutes and TDLR rules change. Rely on the current text of Occupations Code Chapter 1958, the TDLR mold program, TDLR Customer Service (800-803-9202), or a licensed Texas attorney for decisions about a specific project. Last reviewed October 5, 2026.