@Colby Shelhorse I used to remediate mold as part of my job in a residential restoration company. I do not know if you personally would have to provide proof that the mold had been remediated but there are companies that can come in, take indoor air samples, send them to a lab to identify the species and concentrations of spores, write a remediation protocol, and then come back and do a final test after the remediation to make sure it was successful. Mold is ubiquitous meaning it's everywhere all the time, indoors, outdoors, everywhere. What the indoor air quality specialist do is take samples inside in the effected area(s), uneffected area(s), and outside and then compare the samples to see if the concentrations of mold spores are significantly higher in the effected areas as compared to the other samples. If they are, then they will write a step by step procedure on how to remediate the mold.
In my opinion, it's not a big deal and fairly simple to remediate but that could be because I have dealt with it before. The bigger cost usually comes from the repairs aftter the remediation has been completed (i.e. replacing any effected wall board, carpet, painting, etc that was removed or damaged as part of the remediation process).
The cost of the project is largely determined by the square footage that is effected (which typically isn't 100% known until after the IAQ tests).
Background: I'm IICRC certified as an AMRT and AMRS.
