15 U.S. Code § 1639e - Appraisal independence requirements
It shall be unlawful, in extending credit or in providing any services for a consumer credit transaction secured by the principal dwelling of the consumer, to engage in any act or practice that violates appraisal independence as described in or pursuant to regulations prescribed under this section.
No certified or licensed appraiser conducting, and no appraisal management company procuring or facilitating, an appraisal in connection with a consumer credit transaction secured by the principal dwelling of a consumer may have a direct or indirect interest, financial or otherwise, in the property or transaction involving the appraisal.
Any mortgage lender, mortgage broker, mortgage banker, real estate broker, appraisal management company, employee of an appraisal management company, or any other person involved in a real estate transaction involving an appraisal in connection with a consumer credit transaction secured by the principal dwelling of a consumer who has a reasonable basis to believe an appraiser is failing to comply with the Uniform Standards of Professional Appraisal Practice, is violating applicable laws, or is otherwise engaging in unethical or unprofessional conduct, shall refer the matter to the applicable State appraiser certifying and licensing agency.
In connection with a consumer credit transaction secured by a consumer’s principal dwelling, a creditor who knows, at or before loan consummation, of a violation of the appraisal independence standards established in subsections  (b) or (d) shall not extend credit based on such appraisal unless the creditor documents that the creditor has acted with reasonable diligence to determine that the appraisal does not materially misstate or misrepresent the value of such dwelling.
Except as provided under paragraph (2), the Board, the Comptroller of the Currency, the Federal Deposit Insurance Corporation, the National Credit Union Administration Board, the Federal Housing Finance Agency, and the Bureau may jointly issue rules, interpretive guidelines, and general statements of policy with respect to acts or practices that violate appraisal independence in the provision of mortgage lending services for a consumer credit transaction secured by the principal dwelling of the consumer and mortgage brokerage services for such a transaction, within the meaning of subsections (a), (b), (c), (d), (e), (f), (h), and (i).
The Board shall, for purposes of this section, prescribe interim final regulations no later than 90 days after July 21, 2010, defining with specificity acts or practices that violate appraisal independence in the provision of mortgage lending services for a consumer credit transaction secured by the principal dwelling of the consumer or mortgage brokerage services for such a transaction and defining any terms in this section or such regulations. Rules prescribed by the Board under this paragraph shall be deemed to be rules prescribed by the agencies jointly under paragraph (1).
Consistent with the requirements of this section, the Board, the Comptroller of the Currency, the Federal Deposit Insurance Corporation, the National Credit Union Administration Board, the Federal Housing Finance Agency, and the Bureau may jointly issue regulations that address the issue of appraisal report portability, including regulations that ensure the portability of the appraisal report between lenders for a consumer credit transaction secured by a 1-4 unit single family residence that is the principal dwelling of the consumer, or mortgage brokerage services for such a transaction.
Lenders and their agents shall compensate fee appraisers at a rate that is customary and reasonable for appraisal services performed in the market area of the property being appraised. Evidence for such fees may be established by objective third-party information, such as government agency fee schedules, academic studies, and independent private sector surveys. Fee studies shall exclude assignments ordered by known appraisal management companies.
In the case of an appraisal involving a complex assignment, the customary and reasonable fee may reflect the increased time, difficulty, and scope of the work required for such an appraisal and include an amount over and above the customary and reasonable fee for non-complex assignments.
Effective on the date the interim final regulations are promulgated pursuant to subsection (g), the Home Valuation Code of Conduct announced by the Federal Housing Finance Agency on December 23, 2008, shall have no force or effect.
In addition to the enforcement provisions referred to in section 1640 of this title, each person who violates this section shall forfeit and pay a civil penalty of not more than $10,000 for each day any such violation continues.
In the case of any person on whom a civil penalty has been imposed under paragraph (1), paragraph (1) shall be applied by substituting “$20,000” for “$10,000” with respect to all subsequent violations.
The agency referred to in subsection (a) or (c) of section 1607 of this title with respect to any person described in paragraph (1) shall assess any penalty under this subsection to which such person is subject.
 So in original. Probably should be “subsection”.
Section effective on the date on which final regulations implementing such section take effect, or on the date that is 18 months after the designated transfer date if such regulations have not been issued by that date, see section 1400(c) of Pub. L. 111–203, set out as an Effective Date of 2010 Amendment note under section 1601 of this title.