Source: Congressional Budget Office.
Notes: Income categories are defined by ranking all people by their comprehensive household income adjusted for household
size--that is, divided by the square root of the household's size. (A household consists of the people who share a housing
unit, regardless of their relationships.) Quintiles, or fifths, of the income distribution contain equal numbers of people.
Comprehensive household income equals pretax cash income plus income from other sources. Pretax cash income is
the sum of wages, salaries, self-employment income, rents, taxable and nontaxable interest, dividends, realized capital
gains, cash transfer payments, and retirement benefits plus taxes paid by businesses (corporate income taxes and the
employer's share of Social Security, Medicare, and federal unemployment insurance payroll taxes) and employee contri-
butions to 401(k) retirement plans. Other sources of income include all in-kind benefits (Medicare, Medicaid, employer-
paid health insurance premiums, food stamps, school lunches and breakfasts, housing assistance, and energy assis-
tance). Households with negative income are excluded from the lowest income category but are included in the totals.