Federal income taxation of individuals, in a nutshell

How and when is income taxable? To whom is it taxable? This Nutshell summarizes U.S. federal income tax law, defines income, and identifies the different types of deductions. Explains statutory inclusion and exclusion from gross income, profit-related deductions, mixed deductions, personal deductions, and other allowances. Also inquires into the policy and purposes of, and alternatives to, existing legal rules.