Taxation in the US: Income tax (Part 2) Taxable income

Taxable income.

Income tax is imposed as a tax rate times taxable income. Taxable income is defined as gross income less allowable deductions. Taxable income as determined for federal tax purposes may be modified for state tax purposes.

Gross income.

The Internal Revenue Code states that "gross income means all income from whatever source derived," and gives specific examples. Gross income is not limited to cash received, but "includes income realized in any form, whether money, property, or services." Gross income includes wages and tips, fees for performing services, gain from sale of inventory or other property, interest, dividends, rents, royalties, pensions, alimony, and many other types of income. Items must be included in income when received or accrued. The amount included is the amount the taxpayer is entitled to receive. Gains on property are the gross proceeds less amounts returned, cost of goods sold, or tax basis of property sold.

Certain types of income are exempt from income tax. Among the more common types of exempt income are interest on municipal bonds, a portion of Social Security benefits, life insurance proceeds, gifts or inheritances, and the value of many employee benefits.

Gross income is reduced by adjustments and deductions. Among the more common adjustments are reductions for alimony paid and IRA and certain other retirement plan contributions. Adjusted gross income is used in calculations relating to various deductions, credits, phase outs, and penalties.

Business deductions.

Most business deductions are allowed regardless of the form in which the business is conducted. Therefore, an individual small business owner is allowed most of the same business deductions as a publicly traded corporation. A business is an activity conducted regularly to make a profit. Only a few business-related deductions are unique to a particular form of business-doing. The deduction of investment expenses by individuals, however, has several limitations, along with other itemized (personal) deductions.

The amount and timing of deductions for income tax purposes is determined under tax accounting rules, not financial accounting ones. Tax rules are based on principles similar in many ways to accounting rules, but there are significant differences. Federal deductions for most meals and entertainment costs are limited to 50% of the costs (with an exception for tax year 2021, 

The amount and timing of deductions for income tax purposes is determined under tax accounting rules, not financial accounting ones. Tax rules are based on principles similar in many ways to accounting rules, but there are significant differences. Federal deductions for most meals and entertainment costs are limited to 50% of the costs (with an exception for tax year 2021.