When filing your income tax forms with the Internal Revenue Service (IRS), many people wonder if they are doing the right thing by filing jointly with their spouse.

It is almost always to your advantage to file your tax return Married Filing Jointly.  In general, you will pay more combined tax on two separate tax forms than you will on the one joint form.  This statement is true for the majority of taxpayers but there are, as always, exceptions.

In the case of a two income couple where one of them has encountered very large medical expenses during the year, while the other has had minimal medical costs.  Medical expenses are generally deductible after they surpass 7.5% of your adjusted gross income.  By using the smaller figure on a separate return, you may well benefit greatly from this deduction.  On a joint return, however, you may see a reduced benefit or none at all.  Under these circumstances it would always be a good idea to compare the results of both filings.

Another good reason for filing separately is if you believe that your spouse is cheating on your tax returns.  If caught, you can both be held liable on a joint return.  If, however, you file separately, you have no liability for your spouse’s actions.

It is such a general practice to file jointly that, in 2006, the IRS received 53.2 million returns filed jointly, and only 2.5 million returns filed separately by married people.

If you are in doubt, work up both scenarios for comparison.  Most tax preparers have software that automatically checks on this issue.