Taxpayers face a cliffhanger again this year as Congress dithers about extending more than 50 expired tax breaks, including popular deductions for college tuition and fees, mortgage insurance and sales taxes. As we wait for lawmakers to act, we still have time left in the year to make adjustments based on changes that have already happened. Here are four ways to adjust your tax planning:

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1. Reconsider Roths
The volatile stock market means some people might want to take advantage of lower stock values to convert traditional IRAs, funded with pre-tax money, to Roths, which are funded with after-tax money and whose profits can be withdrawn tax-free. They can also redo conversions made last year, when stock values were higher, says Mark Luscombe, principal federal tax analyst for Wolters Kluwer Tax & Accounting US. People can undo, or "recharacterize," a 2014 Roth conversion up until Oct. 15, the extension deadline. Then they have the option to convert back to a Roth if they wait 30 days, or until the year after the original conversion, whichever is later.

2. Amend past returns for same-sex couples
The Supreme Court decision in June that eliminated remaining state marriage bans also ended the tax return two-step that required many couples to file federal returns as married but state returns as singles, says Annette Nellen, professor of accountancy and taxation at San Jose State University. Same-sex couples also have the option — but not the obligation — to amend previous years' returns in the states that previously required them to file as singles, Nellen says.

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3. Avoid rising Obamacare penalties
The penalty for not having had coverage for at least nine months in 2015 is now the greater of 2 percent of household income, or $325 for each adult and $162.50 for each child with a $975 household limit. If you have not signed up already, it is obviously too late to get in nine months of coverage, but there are a number of hardship exemptions. One waives the fine if the lowest-cost coverage available to you exceeds 8 percent of your household's income, says Kirstin Esposito, senior technical manager on the American Institute of Certified Public Accountants (AICPA)'s tax advocacy team.

4. Check your "independent contractor" status
The Department of Labor took aim this summer at employers who may be misclassifying workers as contractors to reduce their companies' tax and health insurance obligations.
A July 15 memo says that most workers being treated as independent contractors were actually employees under the Fair Labor Standards Act. The government issued new guidance that could be used by regulators and courts to order employers to pay back wages, interest and penalties as well as health insurance fines.

Workers who suspect they are being misclassified can alert the Internal Revenue Service or the Department of Labor, or both. The truly bold — or those who do not care about continued employment with the company — can file a Form SS-8 with the IRS to explain why they are an employee rather than a contactor and Form 4852 as a substitute W-2, says. Eva Rosenberg, an enrolled agent.

Employers who classify workers as contractors should consult with a tax professional — and with an attorney if they have deliberately misclassified people, Nellen says. "The risks are really quite high, and they've gone up because of the Affordable Care Act," Nellen says. "You can have significant exposure."