CBO score
Definition
A CBO score is the Congressional Budget Office's nonpartisan estimate of how a bill would change federal spending, revenue, or the deficit, usually over 5 or 10 years. CBO must score nearly every bill that clears a House or Senate committee.
Why it matters
CBO scores are the main independent check on lawmakers' claims about what a bill costs, so sponsors sometimes design provisions specifically to score well within CBO's rules, such as timing tax cuts to expire just before the scoring window ends. Because scores are advisory, not binding, they can also be disputed or ignored by leadership when the underlying vote count already exists.1
Seen in the wild
CBO's 2025 score of the enacted One Big Beautiful Bill Act estimated it would increase primary budget deficits by $3.4 trillion from fiscal year 2025 through 2034, a figure Republican leadership disputed using alternative "current policy baseline" accounting.2