Generally, you must continue to file income taxes for as long as you have any significant income. However, the IRS's definition of significant income varies with your age and filing status. The IRS also sets different thresholds for filing income tax returns, depending on the nature of the income.

Income

To understand filing requirements, it is important to understand what the IRS considers to be income. Under IRS rules, income includes all cash inflow from work, such as wages, salaries, commissions and bonuses. It also includes IRA and 401k distributions, most interest income, rent and royalties. However, qualified distributions from Roth IRAs and designated Roth accounts are not considered income, nor are loans against life insurance cash values.

Single Taxpayers

If you are single, under age 65 and your income is under $9,350, you may not have to file an income tax return. If you are over age 65, that threshold is $10,750. However, if you had over $400 in self-employment income or interest income, you must file a tax return. You must also file an income tax return if you received over $108.28 from a nonprofit entity exempt from withholding Social Security tax or if your employer did not withhold Social Security tax.

Married Taxpayers

For married taxpayers filing joint returns, the threshold depends on the ages of those involved. If both spouses are under age 65, you must file a return if your income is above $18,700 or if any of the other conditions listed above apply. If one spouse is over age 65, then the limit is $19,800. And if both spouses are over age 65, the limit is $20,900.

Considerations

Even if you are not required to file an individual income tax return, you may want to consider doing so. Filing a return may enable you to qualify for a tax refund or credit -- especially if you have earned income for the year and your employer withheld income taxes.