In several states, testing and removing mold are two licences and two companies.

New York licenses mold assessors and remediation contractors separately and bars the same individual from performing both on a property. Florida prohibits an assessor from remediating where they assessed within the previous twelve months. Texas licenses both roles and requires a licence from 25 contiguous square feet of affected area.

Each state publishes its own register, and checking a licence takes a couple of minutes before a visit rather than an argument after one.

Other states regulate mold work lightly or not at all. Absence of a licence requirement is not a verdict on a contractor; it simply means the check has to be done another way.

An independent scope. The assessor decides what has to be done and writes it down; the remediator prices and performs that scope. Neither is marking their own homework, and the document that results is something you can take to a second contractor for comparison.

It also gives you an independent check at the end, since the assessor can verify the completed work against the scope they wrote.

In the three states above, it means they are describing work they may not lawfully do that way, which tells you something before you have paid anyone anything. Elsewhere it is permitted, and the question becomes whether you want the same company deciding the size of the job and quoting for it.

A reasonable middle path in an unregulated state: get the assessment from someone who does no removal, and take that scope out to two remediators.