evidence: The Build Back Better Act would make transformational investments that improve the economic security of the nation’s families and advance solutions to the climate crisis that threaten the planet’s future. These investments would be fully paid for by sensible tax policies and budget savings that require the wealthiest Americans and largest corporations to pay their fair share. Preliminary White House estimates indicate that the Build Back Better Act will reduce deficits by $36 billion over the next decade and by more than $2 trillion in the subsequent decade. [...] The CBO’s topline estimate of the Build Back Better Act’s impact on deficits will diverge from the White House estimates because of how the CBO scores IRS enforcement. The most basic reason for the divergence is that the CBO uses scoring guidelines that exclude savings attributable to program management efforts—such as the tax enforcement initiative included in the Build Back Better Act—but include the cost of funding appropriated to support such initiatives. Following CBO guidelines, the score of the Build Back Better Act’s tax enforcement initiative would include as a cost the approximately $80 billion in new budget authority for the IRS over the next decade but exclude the increase in revenue that would be generated by that investment. The CBO may provide an estimate of the revenue gain; if so, it would most likely not be incorporated into the final score.