Whether your bracket picks are winners or losers in this year's NCAA Tournament, you'd be smart to list any financial gains or losses on your tax return. Winnings are counted as income, and if you itemize deductions you'll want to list any losses as well. 

Gambling winnings for the tax-reporting year should be listed on line 21 of your IRS Form 1040. For any winnings subject to federal income tax withholdings, the payer should provide IRS Form W-2G.

If you lose, that amount needs to be reported on Schedule A of your 1040--line 28. But know that you can't report losses that are more than your winnings. Note that you also can't just combine your winnings with any losses and report the difference. According to CCH, a provider of tax information and software, there needs to be a clear record of everything you lost and won over the course of the year.

Sports betting is legal in at least these four states, Delaware, Nevada, Oregon and Montana. This tax advice also applies to other forms of gambling where you might test your luck, including playing cards at a casino, betting on horses, lottery tickets as well as any raffle prizes. If you ever happen to win big as part of a group or win a large contest payout you will need Form 5754, which is for any person in a group of two or more that split a grand prize. 

Bottom line, as the office pool ramps up it's a good idea to keep your own win-loss score sheet, and lots of other folks will also want to make those payments to avoid penalties. If you have a major gain during the year--from the sale of stock or property, taxable inheritance, or gambling winnings, for instance--you should pay estimated taxes on that income. Social Security beneficiaries with income from other sources, including pensions, might also have to pay. 

Consumer Reports Money Adviser recently offered advice for those paying estimated income taxes quarterly.

For more details about reporting gambling income and losses check out the IRS rules for casual gamblers.

--Maggie Shader