Spending Cap Act of 2011

Spending Cap Act of 2011 - Expresses the sense of Congress that it should enact comprehensive tax reform that lowers marginal rates, broadens the base, and simplifies the tax code to increase economic growth while generating revenues that are in line with the historical average of 18% of Gross Domestic Product (GDP).

Amends the Congressional Budget Act of 1974 (CBA) to establish the discretionary spending limits for FY2012-FY2021 for defense and nondefense categories.

Authorizes the Chairman of the Senate Committee on the Budget to adjust such discretionary spending limits, budgetary aggregates in the most recently adopted concurrent budget resolution, and CBA committee allocations if a bill or joint resolution is reported making appropriations for FY2012-FY2017 that provides funding for overseas deployments and activities undertaken as a result of a declaration of war or congressional authorization of force. Limits such adjustments.

Makes it out of order in both chambers to consider any legislation that includes any provision that would cause total on-budget mandatory spending to exceed specified discretionary spending limits. Exempts from such limits the mandatory components of: (1) Social Security, function 650; (2) Medicare, function 570; (3) Veterans Benefits and Services, function 700; and (4) Net Interest, function 900.

Makes it out of order in both chambers to consider legislation that includes any provision that would cause total mandatory spending for Social Security to exceed specified limits for total outlays for FY2012-FY2021. Makes such requirement inapplicable if the Congressional Budget Office (CBO) determines that projected outlays are expected to exceed such limits due to changes in cost-of-living adjustments (COLAs) contained in present law.

Makes it out of order in both chambers to consider legislation that includes any provision that would cause total mandatory spending for Medicare or for Veterans Benefits and Service to exceed specified limits for total outlays for FY2012-FY2021.

Amends the Balanced Budget and Emergency Deficit Control Act of 1985 (Gramm-Rudman-Hollings Act) to require the Office of Management and Budget (OMB) to make publicly available in the Federal Register an annual report containing expected budget authority and outlays. Requires OMB, if such report shows any category exceeding specified spending caps, to prepare, and the President to issue and include in that report, a sequestration order that reduces budgetary resources by an amount sufficient to bring spending in line with that category's statutory cap. Prescribes requirements for calculating and implementing such sequestration.

Authorizes Congress to override a sequestration order through the passage of a law that either waves or supersedes the spending limitations for that category of federal spending for that fiscal year.

Subjects any motion in the Senate to move to consideration of a bill to waive, modify, or in any way alter a sequestration order (except for defense spending while the nation is engaged in a justified conflict) to a point of order that can only be waived through an affirmative vote of two-thirds of the Members.