NEW YORK (CNNMoney.com) - Tax writers on Tuesday reached official agreement on a tax reconciliation bill that will extend the reduced tax rates on capital gains and dividends and prevent millions of households from falling prey to the alternative minimum tax (AMT).

The bill also includes a controversial provision that will make Roth IRAs available to taxpayers at all income levels.

Extend dividend and capital gains rates Possible savings in 2009 For those with $50k - $75k in income: $58, or 0.4% of tax liability For those with more than $1 million in income: $32,111, or 3.3% of tax liability

AMT relief Provision and impact Boost exemption levels for joint filers to $62,550, from $58,000 Shield 15 million taxpayers from AMT in 2006

Now estimated to cost $69 billion through 2015 by the bipartisan Joint Committee on Taxation, the bill will be protected from filibuster and is likely to be voted on this week, according to Congress Daily, a National Journal publication.

With the exception of some popular provisions like AMT relief, many elements haven't satisfied critics, who contend many of the tax breaks are far too costly and benefit too few taxpayers – namely, upper-income ones.

They also object to the loss of an extension for tuition deduction, which they say could have been paid for if tax writers had left in a provision that would have reduced a key tax break for oil companies and raised $4.3 billion. (The final bill does include a smaller provision pertaining to oil companies that would raise $189 million over 10 years.)

But the tuition deduction may be included in a separate piece of tax legislation, which is expected to include other expiring tax breaks that were taken out of the reconciliation bill.

Originally, Senate Finance Committee Chairman Charles Grassley (R-Iowa) said he wouldn't sign off on the reconciliation bill until elements of the "trailer" bill had been decided. But in a written summary of Tuesday's agreement, Grassley said that he and House Ways and Means Committee Chairman Bill Thomas (R-Calif.) "have an understanding about how other expiring tax provisions will be extended in a second tax bill, including relief for college students paying tuition, teachers buying supplies for their classrooms and the research and development of innovative ideas that benefit our society."

Here is a summary of some of the reconciliation bill's main provisions and how they'll affect your wallet:

The bill will extend for two years the 15 percent rate on long-term capital gains and dividends. For low-income taxpayers, that rate will be 0 percent.

Currently scheduled to expire at the end of 2008, the reduced rates will run through 2010. After 2010, the rates are scheduled to revert to 20 percent for long-term capital gains (10 percent for those in the lowest tax bracket) and one's top income tax rate for dividends.

The JCT estimates the provision will cost $50.8 billion over 10 years.

Proponents of the measure say the reduced rates put more money back in taxpayers' pockets and encourage investment, which in turn spurs job growth and other economic benefits, which can boost tax revenue.

Critics question the correlation between lower investment income rates and economic growth and say the reduced rates primarily benefit high-income taxpayers – since exposure to stocks for middle- and upper-middle income taxpayers tends to be through tax-deferred vehicles like 401(k)s.

The Urban-Brookings Tax Policy Center, for instance, estimates that a taxpayer with an income between $50,000 and $75,000 would save an average of $58 on his tax bill in 2009, or about 0.4 percent of what his total tax liability would have been if the rates weren't extended. But only 23 percent of that income group even have taxable investments -- the average tax cut they'd receive is $255, or about 2 percent of their tax liability.

By contrast, a taxpayer with income of $1 million or more would save an average of $32,111, or about 3.3 percent of what his tax liability would have been. If you just count those with taxable investments in that income group – 81 percent -- the average tax cut they'd receive is $39,448, or about 4 percent of their tax liability.

For those with sizeable dividends in a taxable portfolio, the savings also can be impressive. Say you have a $300,000 portfolio of stocks and mutual funds, where the average dividend yield is 1.8 percent. Your annual dividends would total $5,400 and you'd owe $810 in income tax on them (15% x $5,400). If the reduced rate weren't extended and you're in the 28 percent tax bracket, you'd owe another $702 for a total of $1,512 (28% x $5,400).

Lawmakers will increase for tax year 2006 the AMT income exemption levels that were in effect for 2005. The new exemption levels will be $42,500 for single filers (up from $40,450) and $62,550 joint filers (up from $58,000).

In addition, when calculating whether they're subject to AMT, taxpayers will be allowed to use all nonrefundable personal credits to offset AMT liability. Normally, these credits often end up being disallowed under AMT.

The JCT estimates that the provision agreed to by lawmakers will prevent an additional 15 million taxpayers from falling prey to the AMT in 2006. Tax Policy Center estimates show the majority would come from households with income between $100,000 and $500,000.

The estimated cost of the provision over 10 years is $33.9 billion.

The AMT imposes a higher bill on taxpayers than the regular tax code.

The alternative minimum tax, originally intended for the wealthy, now threatens to catch tens of millions of middle-class taxpayers unless lawmakers continue to increase in the AMT income exemption levels, since the original levels were never adjusted for inflation.

In order to keep the final reconciliation package under its $70 billion spending limit, lawmakers needed to add revenue raisers into the bill.

The most controversial is one allowing all taxpayers, not just those with modified adjusted gross income of $100,000 or less, to convert their traditional IRAs to Roth IRAs.

Proponents of the measure say it will raise revenue since IRA holders must pay taxes on their accounts when they make the conversion. By JCT estimates put out Tuesday, the conversions will yield an additional $6.4 billion in revenue between now and 2015.

But critics say that long-term the provision will be a revenue loser for two reasons: 1) the gains earned in those accounts would grow tax free, whereas in a traditional IRA they would have been taxed as income upon withdrawal; and 2) it's possible those making the conversion would pay their Roth taxes upfront using money from their taxable savings, the money from which is ordinarily taxed every year.