The last major reform of the U.S. tax code came in 1986, when there was divided government in Washington, D.C., as Republicans controlled the White House and the Senate, and Democrats held power in the House.

Since then, the Internal Revenue Code has grown more and more complex, now at almost 4 million words.

"I hope 2013 brings about fundamental tax simplification," said the IRS National Taxpayer Advocate Nina Olson in her year-end report.

It isn't a new message for Olson, who has routinely urged the Congress to do away with what she called a "bewildering array of exclusions, exemptions, deductions, and credits" in the tax code, and replace it with a simpler code that has fewer loopholes and possibly lower overall rates as a result.

"The argument regarding tradeoffs is easier to make if tax reform proceeds on a revenue neutral basis, as it did in 1986," Olson added in her report, which you can find at the IRS web site.

To drive home her point about the complexity of the tax code, Olson said her report shows it now takes businesses and individuals 6.1 billion hours each year - that's not a typo - just to fill out all the needed forms and file those with Uncle Sam.

Olson says 90 percent of Americans now either use computer software to do their taxes, or have someone else prepare their return, mainly because the tax system is much too complicated.

"In this report, we identify tax complexity as the #1 most serious problem facing taxpayers, and we recommend (as we have in prior reports) that Congress vastly simplify the tax code to make tax compliance easier," wrote Olson, who has delivered that message repeatedly to lawmakers in recent years.

Usually what happens in Congressional hearings is that Olson makes her case for tax reform, lawmakers agree with her on the need for simplification, then they turn off their microphone and quickly forget about the idea of tax reform.

Both parties have talked about the need for tax reform in recent months, but it would almost be a surprise for it to happen in 2013.

Meanwhile, the Taxpayer Advocate will continue to urge action.

And Congress will only sort of listen.