; (3) in the flush left matter following paragraph (3), by striking Each such agency or instrumentality and inserting the following: (b) Additional standards Each such agency described under subsection (a) ; and (4) by adding at the end the following new subsection: (c) Exemption for certain mortgage loans Each such agency described under subsection (a) shall exempt, by rule, a real estate appraisal or evaluation conducted in connection with a mortgage loan of $250,000 or less from the standards prescribed under this section, if such loan appears on the balance sheet of the creditor of such loan for a period of not less than 3 years. .