Makes available for the federal government for FY2013 the amount that would have been made available for the fiscal year if the following actions had not occurred:

• sequestration of discretionary spending limits and automatic sequestrations to enforce a specified budget goal under the Balanced Budget and Emergency Deficit Control Act of 1985 (Gramm-Rudman-Hollings Act);
• rescission of the applicable percentage of budget authority provided (or obligation limit imposed) for FY2013 for any discretionary account in divisions A through E of the Consolidated and Further Continuing Appropriations Act, 2013; and
• any presidential sequestration order.

Amends the Gramm-Rudman-Hollings Act with respect to mandatory sequestration, within 15 calendar days after Congress adjourns to end a session, in order to eliminate a budget-year breach, if any, within any category. Requires any amount of budget authority for overseas contingency operations and related activities for FY2014-FY2016 in excess of the levels specified in the Act to be counted in determining whether a breach of the budget has occurred in the security category.

Requires the adjustments to discretionary spending limits for appropriations for discretionary accounts enacted for FY2017-FY2021 that Congress designates for Overseas Contingency Operations/Global War on Terrorism (OCO/GWOT) to be the total of such appropriations in discretionary accounts designated for OCO/GWOT. Specifies limits, however, for any OCO/GWOT adjustments in additional new budget authority for such fiscal years.