While promoting Obamacare, House Speaker Nancy Pelosi encouraged Americans to think of it as a kind of Christmas present. “We have to pass the (health care) bill so that you can find out what is in it,” she told the National Association of Counties in March 2010, days before President Obama signed the Affordable Care Act.

Now we know that the surprise inside Obamacare includes an historic expansion of the IRS, arguably the most hated of federal agencies.

That role was no accident: When Obamacare eventually passed constitutional muster one year ago, it was only because, conservative Supreme Court Chief Justice John Roberts argued, the Affordable Care Act relies on Congress’ power to tax.

Love Obamacare or hate it, Roberts asserted for the majority, it’s really a function of the IRS, and that makes it Congress’s business.

But nobody, not even the IRS itself, is sure precisely how Obamacare will work.

That’s what’s terrifying – or, if you’re Nancy Pelosi, perhaps titillating.

Independent reports suggest there are “47 new things for the IRS to track” in the federal health care regime — “meaning a substantial increase in the amount of work the IRS needs to do.”

That monitoring function requires some planning.

In the weeks after the bill was signed on March 23, 2010, several IRS officials started attending hundreds of White House meetings to define the tax agency’s role in implementing Obamacare.

Watchdog.org searched White House visitor logs for visits by IRS employees, identifying seven IRS officials who logged more than 1,200 White House visits.

For a more detailed look at these visits including two different kinds of charts, view this Watchdog Labs page.

Lost in the more beguiling controversy over whether these meetings are evidence the Obama administration targeted political groups is the more obvious fact: the IRS was — is — helping the White House plot the federal takeover of health care management. IRS Commissioner Douglas Shulman and IRS health care counsel Catherine E. Livingston immediately started logging visits to the White House immediately after the bill was signed. The frequency of Shulman’s 151 visits peaked by October 2010, while Livingston’s 435 visits continued until her departure from the IRS earlier this year.

If you’re a geek, here’s how the numbers look:

  • The seven IRS officials we tracked made about 38 visits in the six-and-a-half months before ACA was signed – about 5.85 visits per month. (We looked at six-and-a-half months of data because the White House has released visitor information beginning. Sept 15, 2009.)
  • At that rate, those seven people would have visited the White House about 243 times over 41.5 months.
  • Instead, those seven officials visited the White House a total of 1,250 times – or roughly five times the number we observed before the ACA signing.

Few of the IRS White House meetings were with President Obama. Most were with staff members and other government officials.

The high number of White House visits by IRS officials likely reflects the complexity of the ACA and its tax implications.

This article originally appeared on Watchdog.org.