Once again, there's a political hullabaloo in Washington over taxes. And, once again, any resolution will come down to the wire.
At issue are more than 50 "temporary" tax breaks that expired at the end of 2013. The majority are business-related, but a handful affect individuals directly.
A reported deal that would have extended some of the breaks for two years -- and others permanently -- got scuttled in the wake of a veto threat from President Obama.
The expectation now is that the House and Senate will approve a one-year retroactive extension in the next two weeks.
If for some reason a one-year extension doesn't go through, that may make for a delayed and confusing start to the tax-filing season, which usually begins in mid-January.
Here are the tax breaks that remain in limbo:
Deduction for teachers' expenses: This measure would let elementary and high school teachers deduct up to $250 for the costs of classroom supplies that they buy. It would be available to all teachers, whether they itemize or not.
Equal treatment of commuting costs: Commuters may reduce their pre-tax income to account for their commuting costs. Under the law, however, those who drive to work and pay for parking are allowed to exclude more ($250 per month) than those who use mass transit ($130 per month). If extended, this measure would provide parity by also allowing mass transit riders to exclude $250 per month.
State and local sales tax deduction: If you itemize your taxes, this measure would let you deduct the state sales taxes you've paid in lieu of state income taxes. This deduction is a boon for itemizers who live in Alaska, Florida, Nevada, South Dakota, Texas, Washington and Wyoming - which are the seven states that don't impose an income tax but do have a general sales tax.
Tuition deduction: Among the many education tax breaks on the books, this one has been available to all tax filers, whether they itemize or not. With it, a taxpayer may deduct up to $4,000 in qualified tuition, fees and related expenses for post-secondary education, such as college and graduate school. The deduction may be taken for yourself, your spouse or your dependents.
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But there are income limitations, and if you take it you may not take other types of education tax breaks, such as the Lifetime Learning Credit. Your deduction also would be reduced by any grants and scholarships received to pay for school, as well as any tax-advantaged money withdrawn from education-savings accounts.
Health coverage tax credit: Among the most confusing of the tax extenders, this dollar-for-dollar credit may be used to offset the cost of 72.5% of qualified health insurance premiums for a family.
But it's only available for 11 types of insurance, and only a select group of people may claim it, including retirees whose pensions are paid by the federal Pension Benefit Guaranty Corp. and unemployed workers who lost jobs that were hurt by international trade (such as when production is shifted to other countries or a flood of imported goods hurts an American industry).
The one-year extension bill introduced this week in the House excludes this health coverage credit.
Deduction for mortgage insurance premiums: People who only put down a small amount to buy a home may be required to pay for mortgage insurance to protect the lender against default. This tax break would let them deduct the cost of their premiums if they itemize their deductions.
Income exclusion for mortgage debt that's been forgiven: When you sell your home for less than what you owe the bank or your home is foreclosed, the bank may agree to forgive the remaining debt you owe. But the IRS typically treats that forgiven debt as taxable income to you. This tax break would allow you to exclude it from your income.
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What's not on the table: Two tax breaks that have yet to expire have nevertheless been at the heart of the tax extender debate.
The Earned Income Tax Credit and the Child Tax Credit were both expanded in recent years, and Democrats have wanted to make those expansions permanent. The expansions of those credits, which benefit low- and moderate-income families, won't expire until the end of 2017. At that point, the value of these credits and their eligibility requirements will revert to their prior parameters.
But their exclusion from the now-scuttled deal to extend some tax breaks for two years and make permanent a number of business tax breaks was cited as a key reason for Obama's veto threat.
--CNN's Deirdre Walsh and Ted Barrett contributed to this report.
