An appraisal is typically only needed when a home is listed for sale. A buyer’s lender will require/order an appraisal and the buyer will pay for it. Buyers and sellers are free to order an appraisal on their own. Still, if they do, the buyer’s lender cannot use the appraisal.
Most appraisals are valid for 90 to 120 days after the home is inspected and appraised. After that time, you can have the appraisal extended, get a recertification of value or have an all-new appraisal done. Getting a property appraised when a purchase or refinance is not involved is generally only useful when you plan to challenge a tax assessment, are engaged in estate planning or are involved in divorce proceedings.