What is a seller obligated to disclose?

It varies from state to state. Under the most restrictive state, the seller and the sellers' broker, if there is one, are required to disclose all facts materially affecting the value or desirability of the property which are known or accessible only to him and which are not known to, or within reach of the diligent attention and observation of the buyer. In the case of residential properties, the seller must provide the buyer with a Real Estate Transfer Disclosure Statement, which specifies the existence and condition of all known physical attributes of the property. Sellers are responsible for disclosing only information within their personal knowledge.