Mandate Prevention Act of 2010

Mandate Prevention Act of 2010 - Amends the Congressional Budget Act of 1974 (CBA) to make it out of order to consider in either chamber of Congress any legislation that would increase the direct costs of federal private sector mandates by an amount that causes the applicable thresholds to be exceeded, unless the legislation: (1) provides new budget or entitlement authority in the House of Representatives or direct spending authority in the Senate for each fiscal year for such mandates in an amount equal to or exceeding the direct costs of each such mandate; or (2) includes an authorization of appropriations in an amount equal to or exceeding the direct costs of such mandates and makes other specified arrangements for up to 10 years during which each mandate shall be in effect under the legislation.

Applies such prohibition to any legislative provision increasing direct costs of a federal private sector mandate (currently, federal intergovernmental mandate only) in any legislation reported by a congressional appropriations committee.

Amends Rule XVIII (The Committee of the Whole House on the state of the Union) of the Rules of the House to state that the Committee of the Whole may be precluded from considering an amendment proposing only to strike an unfunded federal private sector mandate from the portion of the bill then open to amendment only by specific terms of a special order of the House.

Amends the CBA to equalize the threshold between private sector and intergovernmental mandates.