You must disclose that by law, but if it has been remediated PROPERLY there won't be an issue. Mold is not uncommon in most homes, but how they remediate it is the kicker. If they try to use Kiltz or cover it up that's not good, but if your sellers have had a PROFESSIONAL who took care of it and can provide a certificate your buyers should be fine with it. I know this because I happen to be married to a certified industrial hygienist & he deals with this alot in commercial & residential properties. He doesn't remediate, but does the indoor air quality testing for insurance companies.
Here is a link about it... http://www.aiha.org/news-pubs/newsroom/Documents/Facts%20abo
This website is from the American Industrial Hygienist website so it is unbiased (as it would be if coming from a consultant. ) . You may also want to print this and upload as a document in your MLS. Hope this helps..
I'm kinda like previous responders - it may be different in your state, but here on the Left Coast we disclose in the transfer disclosure statement, to which we attach the clearance report from a licensed remediation company that had the results verified by an independent lab.
How many Californian's does it take to put in a light bulb? It takes ten. One to screw the bulb in and nine to write the environmental impact report.
Here in FL this would be disclosed on the Sellers Real Property Disclosure Statement. The seller would indicate that mold was present at one time and then explain how it was taken care of. I would also have the seller include all reports and invoices to show that the situation was taken care of by professionals. This should help ease the fears of prospective buyers and protect the sellers in the future because they made full disclosure. Hope this helps!
If it was fixed then do you need to disclose it? If you replaced the water heater, do you have to disclose that? Luckily in 23 years I have never had to worry about mold abatement so I'll be curious of the answers you get. If you added it to the Property Disclosure that should suffice as disclosure.