Who must file. Generally, the amount of income you can receive before you must file a tax return has increased. Table 1 shows the filing requirements for most taxpayers.

Exemption amount. The amount you can deduct for each exemption has increased from $3,400 in 2007 to $3,500 in 2008.

Exemption phaseout. You lose part of the benefit of your exemptions if your adjusted gross income is above a certain amount. For 2008, the phaseout begins at $119,975 for married persons filing separately; $159,950 for single individuals; $199,950 for heads of household; and $239,950 for married persons filing jointly or qualifying widow(ers). However, in 2008, you can lose no more than of the amount of your exemptions. In other words, each exemption cannot be reduced to less than $2,333.

Exemption for individual displaced by Midwestern disaster. You may be able to claim a $500 exemption if you provided housing to a person displaced by a Midwestern disaster. For more information, see Exemption for Individual Displaced by a Midwestern Disaster.

Standard deduction increased. The standard deduction for most taxpayers who do not itemize their deductions on Schedule A of Form 1040 is higher in 2008 than it was in 2007. The amount depends on your filing status. In addition to the annual increase due to inflation adjustments, your 2008 standard deduction is increased by:

You can use the 2008 Standard Deduction Worksheet near the end of this publication to figure your standard deduction.

Itemized deductions. Some of your itemized deductions may be limited if your adjusted gross income is more than $159,950 ($79,975 if you are married filing separately). See Who Should Itemize, later.

Divorced or separated parents. Beginning with 2009 tax returns, a noncustodial parent claiming an exemption for a child can no longer attach certain pages from a divorce decree or separation agreement instead of Form 8332 if the decree or agreement was made after 2008. This noncustodial parent will have to attach Form 8332 or a similar statement signed by the custodial parent and whose only purpose is to release a claim to exemption. See Children of divorced or separated parents under Exemptions for Dependents.

Taxpayer identification number for aliens. If you are a nonresident or resident alien and you do not have and are not eligible to get a social security number (SSN), you must apply for an individual taxpayer identification number (ITIN). Your spouse also may need an ITIN if he or she does not have and is not eligible to get an SSN. See Form W-7, Application for IRS Individual Taxpayer Identification Number. Also, see Social Security Numbers for Dependents, later.

Photographs of missing children. The Internal Revenue Service is a proud partner with the National Center for Missing and Exploited Children. Photographs of missing children selected by the Center may appear in this publication on pages that would otherwise be blank. You can help bring these children home by looking at the photographs and calling 1-800-THE-LOST (1-800-843-5678) if you recognize a child.

This publication discusses some tax rules that affect every person who may have to file a federal income tax return. It answers some basic questions: who must file; who should file; what filing status to use; how many exemptions to claim; and the amount of the standard deduction.

Who Must File explains who must file an income tax return. If you have little or no gross income, reading this section will help you decide if you have to file a return.

Who Should File will help you decide if you should file a return, even if you are not required to do so.

Filing Status helps you determine which filing status to use. Filing status is important in determining whether you must file a return, your standard deduction, and your tax rate. It also helps determine what credits you may be entitled to.

Exemptions, which reduce your taxable income, are discussed in Exemptions .

Exemptions for Dependents explains the difference between a qualifying child and a qualifying relative. Other topics include the social security number requirement for dependents, the rules for multiple support agreements, and the rules for divorced or separated parents.

Standard Deduction gives the rules and dollar amounts for the standard deduction — a benefit for taxpayers who do not itemize their deductions. This section also discusses the standard deduction for taxpayers who are blind or age 65 or older, and special rules for dependents. In addition, this section should help you decide whether you would be better off taking the standard deduction or itemizing your deductions.

How To Get Tax Help explains how to get tax help from the IRS.

This publication is for U.S. citizens and resident aliens only. If you are a resident alien for the entire year, you must follow the same tax rules that apply to U.S. citizens. The rules to determine if you are a resident or nonresident alien are discussed in chapter 1 of Publication 519, U.S. Tax Guide for Aliens.