The amount of time corporate CEOs spent pushing for an income-tax-hiking resolution to America’s fiscal cliff was well worth it for their companies—particularly because it re-opened tax loopholes worth $10.6 billion for multinationals.

Alongside the big picture fiscal cliff resolution, a package of miscellaneous tax breaks was also renewed. It’s referred to in Washington as “extenders.” (See the whole breakdown.) Many of these breaks prompted incredulity—a tax break just for NASCAR?—or were identified as typical Washington pork barrel spending. But while the headline grabbers were multi-million-dollar giveaways for Hollywood filmmakers or American Samoa, the most notable breaks really were for American corporations doing business abroad.

The extenders package emerged from the Senate Finance Committee with bipartisan support in the summer of 2011, earning plaudits from the conservative Heritage Foundation for eliminating 21 tax breaks. It was designed as a vehicle for bipartisan compromise, containing everything the two parties in the Senate felt was an easy “yes,” including business-friendly stimulus, the yearly fix of the Alternative Minimum Tax and a healthy dosage of corporate largesse. It included economically important provisions like the Research & Development tax credit, which was the most expensive part of the bill at $14 billion; individual incentives like tax breaks for student loans; and politically untouchable provisions like the adoption tax credit and hiring incentives for veterans.

While Republicans in the House objected to tax credits supporting green energy, the general sense among legislators was that agreement was close between the tax writers in both chambers. As the fiscal cliff moved into an endgame after the election, most analysts expected the extenders would be included in any deal, thanks to bipartisan favor in the Senate and House Republicans clamoring to pass them, not to mention the support of a dozen influential lobbies, including green energy investors favored by the Obama administration and influential Wall Street advocates.

“It’ll go in the big fiscal compromise,” Congressional Quarterly tax writer Sam Goldfarb warned presciently in early December, “and you won’t hear a lot about it unless someone’s like, ‘they passed a NASCAR tax break in this big deficit reduction deal?'”

Despite some last minute game-playing, the extenders were included in the compromise. The endless fight over raising taxes on the wealthy allowed the various breaks to pass without intense scrutiny. While any of the most questionable regionally-targeted breaks—like the 9/11-inspired financial breaks for building in New York City’s financial district—might have been targeted for elimination, legislators feared pulling a thread at the last minute could unravel the whole sweater.

While there wasn’t much to the idea that policy “uncertainty” actually held back economic growth, if you actually asked companies what worried them, it was ensuring the renewal of tax incentives for research and buying new equipment that were enacted as part of the 2009 economic stimulus and were now found in the extenders. But the larger reason that major business leaders joined the White House in media events to pressure Congress to raise income taxes and make a fiscal cliff deal is the promise of corporate tax reform that would make it easier for multinational corporations to move money around.

They got two major elements of that in the extenders. A provision allows US companies operating overseas to convert “passive” profits like interest payments and rents into lower-tax “active” investment vehicles, largely benefitting financial services companies or industrials, like GE, with major financial units. Another provision allows tech and pharmaceutical companies to move intellectual property to subsidiaries in low-taxed or no-tax countries. These are the kinds of rules that allow companies like Pfizer and Google to pay low taxes, and recently attracted public censure for Starbucks in the United Kingdom.

These advantages are some of the reasons that corporations made such a killing in 2012 while paying so little in tax. But tax expenditures like the breaks in the extenders have attracted the scrutiny of fiscal wonks and lawmakers eager to take up comprehensive tax reform, and the logic of future fiscal deal-making leads toward a major overhaul. That will be a bonanza for corporate lobbyists, but with higher stakes. On one hand, the push to move the US away from its global tax regime could be a major victory for multinationals; on the other hand, the next mandate is more likely to be closing breaks than re-opening them.