Certain types of income posted strong gains between 2004 and 2005. Net capital gains climbed 41%, and taxable interest rose 29.5%, while net partnership and S corporation income gained 27.3%.

Taxable income totalled $5.1 trillion in tax year 2005, up 10% from the prior year. Total income tax increased for a second straight year, rising 12.4% to $934.8 billion. Between tax years 2003 and 2004, total income tax rose 11.2%, the first increase in 4 years.

The alternative minimum tax (AMT) grew 33.7% between 2004 and 2005 to $17.4 billion. Four million taxpayers paid the AMT in 2005, compared to almost 3.1 million in tax year 2004.

This edition of the quarterly Bulletin also included articles about:

- Growth trends in partnerships: Between tax years 2004 and 2005, the number of partnerships rose 8.5% to about 2.76 million. The number of partners increased just 4.2% to about 16.21 million in tax year 2005. Meanwhile, income rose at a much faster rate. Total partnership net income climbed 42% to $546.2 billion in tax year 2005.

- Municipal bond issuance: State and local governmental entities issued about $475 billion of tax-exempt bonds in calendar year 2005, up 11.9% from the prior year. Governmental bonds accounted for about three-quarters of the total, while private-activity bonds represented the remainder.

- A look at private foundations: The number of private foundations that filed Form 990-PF remained nearly the same between tax years 2003 and 2004,while the number of nonexempt charitable trusts treated as private foundations that filed the return increased by 12%. In tax year 2004, private foundations distributed $27.6 billion in contributions, gifts, and grants and other outlays for charitable purposes, while nonexempt charitable trusts distributed $314 million.

- Recent data on charities: For tax year 2004, nonprofit charitable organizations exempt from income tax under Internal Revenue Code Section 501(c)(3) filed more than 276,000 information returns, an increase of 5% from 2003. These organizations held more than $2.0 trillion in assets, a real increase of 5% from the previous year and 52% over the past decade.

- Corporate foreign tax credits: For tax year 2003, US corporations claimed $50 billion in foreign tax credits. Corporations that claimed a foreign tax credit paid $140.5 billion in worldwide income taxes on $424.5 billion in worldwide taxable income.