By comparison, Trump -- who recently revised his plan to offer tax cuts for individuals and corporations -- would increase the debt by roughly $5.3 trillion over 10 years, the group’s report said. That figure is less than half the $11.5 trillion that the group estimated for his original plan.

Over the past week, both campaigns have given details about their tax plans to Washington-based policy analysts that differed from what they’ve made public. On Sept. 15, a Trump campaign adviser told the Tax Foundation that a key provision of Trump’s plan -- a 15 percent tax rate for certain types of businesses -- would apply only to corporations. But at the same time, the New York Times reported, Trump’s campaign told a small-business advocacy group that the rate would be available to small businesses.

“Significant ambiguity remains under Trump’s plan” on that issue, the budget-policy group’s report said.

Pass-Through Plan

The information that Clinton has shared with the Committee for a Responsible Federal Budget is somewhat different. For example, one proposal -- to levy an existing 3.8 percent “net investment income tax” on income from partnerships, limited liability companies and other businesses known as “pass-throughs” -- has been publicly available, though little-noticed. It borrows from a proposal by President Barack Obama’s administration.

“They shared it with us a month ago,” said Marc Goldwein, the Committee for a Responsible Federal Budget’s senior policy director, referring to Clinton’s campaign. “It’s not something they’re advertising.”

Pass-through businesses don’t pay taxes themselves, but pass their earnings through to their owners, who are taxed at their individual tax rates. The pass-through structure is used extensively by small businesses, investment partnerships and giant money managers like Fidelity Investments, or FMR LLC. Under current law, such businesses have been able to escape the investment-income tax, which was created by the Affordable Care Act. Ending that would generate about $250 billion in revenue over 10 years, the committee estimates.

Risk Fee

Another Clinton proposal -- a risk fee for banks -- was first proposed several months ago, though she provided little detail, the policy group said. It turns out the fee would be almost double what analysts expected, the report said. Analysts assumed her proposal would be similar to one from Obama, who had proposed a fee of seven basis points on the assets of large financial institutions. (A basis point is the equivalent of 0.01 percentage point.)

Instead, Clinton’s fee will use a sliding scale, based on size and risk, that averages about 13 basis points -- almost twice as large as Obama’s proposal, the report said. As a result, the fee is estimated to raise about $50 billion more over 10 years.