By law, the thresholds for the marginal federal income tax brackets must change each year to keep pace with inflation. For 2009, those brackets are as follows:

Taxpayers Filing as Single:

• 10% on taxable income between $0 and $8,350
• 15% on taxable income between $8,350 and $33,950; plus $835
• 25% on taxable income between $33,950 and $82,250; plus $4,675
• 28% on taxable income between $82,250 and $171,550; plus $16,750
• 33% on taxable income between $171,550 and $372,950; plus $41,754
• 35% on taxable income over $372,950; plus $108,216

Taxpayers Filing as Married Filing Jointly or Qualifying Widow(er):

• 10% on taxable income between $0 and $16,700
• 15% on taxable income between $16,700 and $67,900; plus $1,670
• 25% on taxable income between $67,900 and $137,050; plus $9,350
• 28% on taxable income between $137,050 and $208,850; plus $26,637.50
• 33% on taxable income between $208,850 and $372,950; plus $46,741.50
• 35% on taxable income over $372,950; plus $100,894.50

Taxpayers Filing as Head of Household:

• 10% on taxable income between $0 and $11,950
• 15% on taxable income between $11,950 and $45,500; plus $1,195
• 25% on taxable income between $45,500 and $117,450; plus $6,227.50
• 28% on taxable income between $117,450 and $190,200; plus $24,215
• 33% on taxable income between $190,200 and $372,950; plus $44,585
• 35% on taxable income over $372,950; plus $104,892.50

Taxpayers Filing as Married Filing Separately:

• 10% on taxable income between $0 and $8,350
• 15% on taxable income between $8,350 and $33,950; plus $835
• 25% on taxable income between $33,950 and $68,525; plus $4,675
• 28% on taxable income between $68,525 and $104,425; plus $13,318.75
• 33% on taxable income between $104,425 and $186,475; plus $23,370.75
• 35% on taxable income over $186,475; plus $50,447.25

One of the things you'll notice about these tax brackets is that our federal income tax system is progressive -- tax rates increase as taxable income increases. This means that each taxpayer reporting the same filing status actually pays tax at the same rate for the same income. So, for example, you and Warren Buffett actually pay the same tax rate on the first $10,000 of taxable income.

Marginal tax brackets are generally announced each fall before the tax year begins (for example, these 2009 tax brackets were announced in the fall of 2008). The brackets for 2010 have already been announced; as expected, the brackets are relatively the same due to low inflation. With that in mind, expect to see similar tables next season.