Intergovernmental Mandate Relief Act of 1991

Intergovernmental Mandate Relief Act of 1991 - Prohibits a Federal agency or court from requiring compliance in any fiscal year by State or local governments with any intergovernmental regulation unless provisions of law have been enacted which compensate such governments for additional direct costs incurred by such compliance. Declares that the compensation requirement may be waived by the enactment of a joint resolution of the Congress.

Requires the Director of the Congressional Budget Office (CBO) to estimate such additional direct costs and include such estimates in annual reports to the President and the Congress.

Requires congressional committees to propose amendments to significant laws for which regulations will be promulgated containing provisions to compensate State and local governments for additional direct costs of complying with any intergovernmental regulation which takes effect on or after enactment of this Act.

Establishes procedures for Federal agencies to reimburse State governments for additional direct costs and for State governments to reimburse local governments for such costs.

Amends the Congressional Budget Act of 1974 to require CBO to prepare cost estimates for bills or resolutions which are likely to cost State and local governments $100,000,000 (currently, $200,000,000) or more annually.