By Chris Farrell

For all the squabbling over the Bush tax cuts, you might think they're the only thing on Congress' agenda for the lame duck session that started Nov.15th. But lawmakers also must address a handful of other crucial tax measures that could affect wallets at all income levels.

Put simply: Taxpayers could well be on the hook, but they won't know by how much until feuding Congressional leaders finally cut a deal.

The accountants at Grant Thornton LLP say the loose ends make year-end tax planning trickier than usual because "acting before knowing what Congress will do renders some planning a crap shoot." One thing for sure, the clock is ticking since the 1040 form many Americans use to file their taxes should be available for download in early December.

The high-profile Bush tax cut fight largely comes down to this: President Obama wants to preserve the cuts for families earning $250,000 or less but not for families making more than $250,000.  Republicans, fresh off huge gains in mid-term elections, are eager to make all the cuts permanent. The likely outcome: Compromise.

"There may be a whole host of ways to compromise around those issues," Obama said Friday. That same day Republican Senate Minority Leader Mitch McConnell issued a statement, saying, "I'm willing to listen to what the president has in mind for protecting Americans from tax increases."

The deadline for making a decision on the Bush cuts is Dec. 31, or else they expire and income taxes will go up.

The same deadline holds for lower-profile tax issues that would be costly for many taxpayers if Congress does not act: the estate tax, the taxes paid on dividends and capital gains and the alternative minimum tax. Compromise probably will be the outcome, but before it reaches that point there will be more high-torque rhetoric and political posturing. As with the Bush tax cut debate, Republicans will want to flex their mid-term muscle, and the Democrats and Obama will want to stand their ground.

Estate Tax: You've probably heard the wisecracks about the estate tax for 2010: Grandma, Grandpa, if you're really wealthy please die in 2010? Or, if it's Dec. 31st, time to pull the life support?

Okay, they aren't that funny, but they seemed amusing back in 2001 when lawmakers lowered the estate tax rate and boosted the amount of money exempt from the tax until it expired in 2010. The rate went from 55% in 2001 to 45% in 2009, before the tax disappeared completely this year. The amount of money that could be passed on tax-free also rose steadily, from $1 million to $3.5 million ($7 million for couples) in 2009. This year, lucky heirs can pocket the entire estate without handing anything over to Uncle Sam. But here's the weird part: In 2011 the estate tax reverts back to 2001 rules — a 55 percent rate and only $1 million escapes taxation.

What will Congress do? Last year, House Democrats, with the Administration's backing, passed a permanent extension of the 2009 rates and exemption, but the bill foundered in a contentious Senate battle. Although Sen. Jon Kyl (R-Ariz.) and Sen. Blanche Lincoln (D-Ark.) introduced a bill that set a top rate of 35 percent on estates worth over $5 million ($10 million for couples), many Republicans wanted to get rid of it all together and refused to back any revival of the tax. That makes this year's negotiations difficult to divine. Many still oppose what they've renamed the "death tax", but they don't want it to shoot back up as it would if Congress can't forge an agreement. With the odds against repeal, something along the lines of permanently extending the 2009 rules or resurrecting the Kyl/Lincoln proposal (even though Sen. Lincoln lost her seat) seems likely.

Since most tax experts and financial planners expected lawmakers to deal with the situation long before now, however, few are willing to place bets on the outcome. "Who knows what will happen?" says William Gale, economist at the Brookings Institution and a co-author of several scholarly papers on the estate tax.

Capital gains and dividends: For taxpayers who own stocks, bonds or other investments, the rate on capital gains and dividends has been capped at 15 percent. The rate was set as part of the Bush tax cuts and will expire at yearend if Congress doesn't act. The capital gains rate will rise to 20 percent. Even more striking, the tax rate on dividends will rise to equal the rate a taxpayer pays on ordinary income, up to a high of 39.6 percent. The shift will disproportionately influence older investors. According to the Tax Foundation taxpayers over age 55 accounted for 71 percent of all dividend income earned in 2008. "The dividend increase has gotten a lot less attention than it should have," says Alan Viard, a resident scholar at the American Enterprise Institute.

What will Congress do? The issue is tied up with the broader debate over the Bush tax cuts on ordinary income. In recent years there has been talk of capping both at 20 percent. But at the moment the most likely outcome is that the 15 percent rate on both capital gains and dividends will remain, assuming there is at least a temporary extension of the 2001 and 2003 Bush cuts.

Alternative Minimum Tax: In 1969 average Americans were outraged that a small group of the wealthiest citizens didn't pay any income tax. Congress responded with the Alternative Minimum Tax — better known as the AMT -- to guarantee that the wealthy couldn't escape a tax bill. But in recent years, an increasing number of middle-class taxpayers have been hit by it as well.

The AMT basically is a parallel tax system. It requires taxpayers to recalculate their taxes under the AMT rules by adding back in certain items, such as the deduction for state and local taxes and the standard deduction. They then figure out how much tax would be owed using  AMT rates, which are 26% on the first $175,000 and 28% above that. Filers pay whichever tax bill is higher, their regular income tax or the AMT.

The AMT didn't matter for middle-income folks for years because they owed more on their regular income tax bill. Congress, however, didn't adjust the AMT for inflation and, over time, higher real estate values, steeper local tax payments, increased incomes, the proliferation of credits and deductions, and the 2001 and 2003 tax cuts pushed more middle- and upper-middle-income filers into AMT territory.

"If Congress doesn't do anything at some point in time we could all be on the AMT because it isn't indexed for inflation," says Jason Fichtner, senior research fellow at the Mercatus Center at George Mason University.

To prevent that unpalatable outcome, Congress has repeatedly adopted a "patch" that raises the income level automatically exempt from the AMT, usually for a year or two. The AMT may have been designed to make sure that Bill Gates and Steve Jobs paid their fair share of income taxes, but without a patch for 2010 some 21 million taxpayers will pay the AMT rates. That's unlikely to happen, however. All signs are that another new temporary patch will be passed.

On Nov. 9 the four leading tax powers on Capital Hill — Sen. Max Baucus (D-Mont.), Rep. Sander Levin (D-Mich), Sen. Chuck Grassley (R-Iowa) and Rep. Dave Camp (R-Mich) — wrote Douglas Shulman, commissioner of the Internal Revenue Service, about the AMT. They assured him "that Congress is working on legislative relief." That's Washington speak for a new patch is on the way. They plan on setting the exemptions for 2010 at $47,450 for individuals and $72, 450 for married taxpayers filing jointly. The exemptions—the equivalent of the standard deduction on the regular income tax--are currently are $33,750 and 45,000, respectively.

As for a permanent fix, that, too, is anyone's guess. It will have to happen sooner or later, but doing so would require Congress to find at least $1 trillion in new revenue to fund the change or add the cost to the reported deficit.

"The president did propose a permanent patch," Viard says. "But that has fallen on deaf ears." Leaving one more tax fight to eventually be fought.

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Chris Farrell is economics editor for the nationally syndicated public radio program Marketplace Money. He is the author of The New Frugality: How to Consume Less, Save More, and Live Better (Bloomsbury Press)