As a presidential candidate, Donald Trump promised to set low tax rates to encourage U.S. companies to bring back funds they had stashed overseas.

Some companies store income overseas -- rather than bringing it home -- for fear of incurring relatively high U.S. tax rates.

During the campaign, Trump said his tax plan "will provide a deemed repatriation of corporate profits held offshore at a one-time tax rate of 10 percent."

On Dec. 19 and 20, the Senate and the House passed the final version of the tax bill, which will go to the president for his signature.

Under the bill that passed, U.S. businesses that are holding assets overseas would be allowed to repatriate those assets at 8 percent, or 15.5 percent for liquid assets.

That's different than the 10 percent rate Trump had promised, but one of the two rates is actually lower than that -- 8 percent.

"The exact number isn't far off, but on average, it's not far off," said Patrick Newton, a spokesman for the Committee for a Responsible Federal Budget.

Despite the difference in Trump's proposed tax rates and those in the bill, the two rates in the bills average out to close to the 10 percent he'd proposed during the campaign. We rate this a Promise Kept.

As a presidential candidate, Donald Trump proposed creating a one-time tax for "repatriating" income held in foreign countries by United States companies. In his fiscal 2018 budget proposal, Trump reiterated that that's still his plan.

What does this mean? As the Urban Institute-Brookings Institution Tax Policy Center explains it, there are two types of tax systems -- territorial and worldwide. Generally speaking, a territorial system would tax all income earned from investments within the United States but exempt income from investments outside the United States. By contrast, a worldwide system would tax all income regardless of where it was generated.

Currently, the United States has what the Tax Policy Center calls a hybrid system, with aspects of both. Without getting too far into the weeds, companies are currently able to avoid U.S. taxes by keeping income they earn with foreign subsidiaries in overseas accounts. Once that money is brought home, or "repatriated," it is taxable at the full U.S. corporate tax rate, adjusted to give a credit for any foreign taxes already paid.

The result is that the current system "effectively exempts a significant share of foreign profits," the Tax Policy Center says.

Trump's plan would allow these companies to bring that overseas money back home all at once, with a special, lower-than-usual tax rate.

In his budget proposal, Trump pledged to "end the penalty on American businesses by transitioning to a territorial system of taxation, enabling these businesses to repatriate their newly earned overseas profits without incurring additional taxes. This transition would include a one-time repatriation tax on already accumulated overseas income."

This mention clearly reiterates Trump's support for the idea, minus the specificity of the 10 percent figure cited during the campaign.

Still, there is no actual tax legislation yet to carry out Trump's priorities, and Congress will have to pass measures before Trump can sign them into law. Still, his decision to mention the proposal in the budget document moves this promise to In the Works.