The annual federal budget deficit is the amount by which federal government outlays exceed revenues for a given fiscal year, with surpluses generated when revenues exceed outlays. Budget deficits or surpluses are often used to gauge national fiscal health, as budget balances over time determine levels of federal debt held by the public, and corresponding net interest payments required for debt service. During an economic downturn, budget deficits could be viewed as effective fiscal policy, with lawmakers enacting tax cuts and increasing federal spending to simulate economic activity. This book examines to what extent major legislative changes from 2001 to 2009 caused the budget to move from surplus to deficit.