Reducing the Size of the Federal Government Through Attrition Act of 2011

Reducing the Size of the Federal Government Through Attrition Act of 2011 - Requires the Office of Management and Budget (OMB) to take appropriate measures to ensure that: (1) the total number of federal employees, beginning in FY2015, does not exceed 90% of the total number of such employees as of September 30, 2011; (2) agencies do not appoint, until the end of FY 2014, more than one employee for every three employees retiring or otherwise separating from government service; and (3) there is a reduction in the amount expended for service contracts in each fiscal year equal to the reduction for the amount expended for the reduced federal workforce.

Requires OMB to continuously monitor all agencies and make a determination whether the total number of federal employees exceeds the limitation imposed by this Act. Prohibits a federal agency from filling any vacancy unless OMB provides written notice to the President and Congress that the number of federal employees does not exceed the limitation established by this Act.

Allows the President to waive the workforce limitations imposed by this Act if the President determines that the existence of a state of war or other national security concern or the existence of an extraordinary emergency threatening life, health, public safety, property, or the environment so requires. Allows the President additional discretion to waive such workforce limitations if the President determines that the efficiency of a federal agency or the performance of its critical mission so requires.

Requires OMB to report annually to Congress on the effect of the reductions in the federal workforce required by this Act on programs, activities, and services, paying special attention to any reductions that will harm national security or endanger life, public health or safety, property, or the environment.