What is budget reconciliation?
The procedure that lets a bill pass the Senate with 51 votes — and its limits.
Reconciliation is a special procedure created by the Congressional Budget Act of 1974. Its defining feature is that reconciliation bills cannot be filibustered, so they pass the Senate with 51 votes instead of 60.
How a bill becomes a reconciliation bill
Congress must first pass a budget resolution containing reconciliation instructions, which direct named committees to produce legislation changing spending or revenue by a specified amount. Only legislation produced under those instructions qualifies.
The Byrd rule
Provisions that are "merely incidental" to the budgetary effect can be struck by the Senate parliamentarian on a point of order. In practice this removes policy provisions that do not directly change spending or revenue, which is why reconciliation bills often arrive on the floor smaller than they started.
Frequency limits
Congress can generally use reconciliation once per budget resolution for each of spending, revenue, and the debt limit. This is a scarce procedural resource, which is why its use signals that legislation is a leadership priority.