Implementing last year’s financial overhaul law could cost the federal government as much as $2.9 billion over five years, according to a summary of a coming Government Accountability Office report obtained by the Journal.

Not all of that would come from taxpayer pockets. Six of the 11 agencies charged with implementing the law are fully or partly funded by assessments on the entities they oversee, one fully by revenues collected, and only three fully or partly by Congressional appropriations. The Consumer Financial Protection Bureau receives all its funding from the Federal Reserve, which in turn gets 100% of its budget from assessments and other revenues — not from taxpayers. But financial firms will see their bills to the government go up, and critics say too steep a burden could hurt the industry’s competitiveness.

Nonetheless, House Republicans plan to use the numbers in the forthcoming GAO study to bolster their argument that the new law, known as Dodd-Frank, will be a drag on the economy. The House Financial Services subcommittee on Oversight and Investigations is holding a hearing on the issue this Wednesday, the same day the full GAO study requested by that panel’s Republicans will be released.

The GAO report, requested by Republicans leading the hearing, estimates that the first year of Dodd-Frank implementation will cost the 11 agencies a total of about $974 million, according to a summary of the report included in a GOP memo about the hearing. Using that as an annual baseline, the GAO estimates that Dodd-Frank implementation will cost about $2.9 billion over five years.