Fannie Mae will offer borrowers in homes built with toxic drywall an extension to the current six-month mortgage forbearance, if needed. Servicing guidance released by Fannie on Monday clarifies that the extended period is to allow for removal of the drywall. Homes built with defective drywall from 2001 to 2008 may cause atypical blackening or corrosion of copper electrical wiring in appliances and pipes. It may also lead to health problems. Efforts to trace homeowner compensation to defective drywall manufacturing companies in China is so far proving to be a dead end. In July, Fannie cleared servicers to provide a six-month forbearance for borrowers experiencing financial hardships because of drywall problems. Freddie Mac did the same. During the forbearance period, borrowers do not have to make a mortgage payment without credit score damage. Effective immediately, Fannie Mae will consider an extension. If the servicer recommends to Fannie additional forbearance is needed, the servicer must reevaluate the borrower's financial condition and any progress made to fixing the drywall. If Fannie Mae denies the extension, the servicers must work with the borrower to determine an appropriate foreclosure prevention alternative but resume credit reporting. Write to Jon Prior.