Marriage ... baby ... divorce ... death. Sooner or later, we will all experience one or more of these life-changing events. We will be jolted by joy, sorrow and a million other emotions associated these major events. What we are less likely to think about, until it's time to prepare income tax returns, is how circumstances can affect our filing status.

Why is your filing status important? Because it determines your tax, and whether you are eligible for certain deductions and credits. The IRS recognizes five filing statuses, spelled out in IRS Publication 501. In general, your filing status depends on whether you are considered married or unmarried.

Sounds simple enough, but there are layered nuances to each status. Here's a brief rundown of each status. If you think more than one filing status applies to you, then you should choose the one that will give you the lowest tax.

  • Single. You are considered single if you are not married and you don't qualify for another filing status. This includes people who are divorced. If you are divorced under a final decree by the last day of the year, you are considered unmarried for the whole tax year. If you were widowed before Jan. 1, 2016, and did not remarry before the end of the year, your filing status may be single unless you have dependent children.
  • Married Filing Jointly. You can choose this status if both you and your spouse agree to file a joint return, meaning you report your combined income and deduct your combined allowable expenses. Both spouses generally must sign the return, but conditions apply if your spouse is serving in a combat zone, is too ill to sign or is mentally incompetent. If your spouse died during the year and you didn't remarry before the end of the tax year, you can file a joint return for yourself and your deceased spouse but must indicate that you are "filing as surviving spouse" in the area where you sign the return.
  • Married Filing Separately. This filing status may benefit you if you want to be responsible only for your own tax, if you and your spouse don't agree to file a joint return, or if it results in less tax than filing a joint return. There are several special rules that apply if you choose this filing status that may result in you paying more tax on a separate return than if you use another filing status that you qualify for. Your tax preparer should figure your tax both ways (on a joint return and on separate returns) to make sure you are using the filing status that results in the lowest tax for both of you.
  • Head of Household. You qualify for this status if you are unmarried, you paid more than half the cost of keeping up a home for the year, and a "qualifying person" (usually a child) lived with you in the home for more than six months of 2016. This qualifying person probably raises the most "what if" questions about the head of household status. "What if my parent came to live with me in 2016?" "What if my live-in girlfriend's child under 18 lived with us all year?" "What if my husband and I separated and he didn't live in the home during the last six months of the year?" "What if I had a baby or adopted a child during the tax year?"

To also qualify for head of household status, you may be "considered unmarried" on the last day of the year if you meet certain tests. The IRS cites specific criteria that could help determine the answers to these questions, but it's always best to consult with your tax pro.

  • Qualifying Widow(er) With Dependent Child. You are eligible to file using this status if you meet five criteria: 1) You were entitled to file a joint return with your spouse for the year your spouse died. 2) Your spouse died in 2014 or 2015 and you didn't remarry before the end of 2016. 3) You have a child or stepchild for whom you can claim an exemption. 4) This child lived in your home all year, except for temporary absences. 5) You paid more than half the cost of keeping up a home for the year.

It's easy to go along year-after-year checking off the same filing status-- until a life-changing event occurs and we're left wondering what to do. Don't leave it to chance, guesswork, or the advice of well-meaning friends or family members. It helps to seek the guidance of a tax pro to help you navigate the tax ramifications, while you spend the rest of your time navigating your circumstances.

Because life happens.