Income left after paying taxes is referred to as disposable income. Disposable income is thus total personal income minus personal current taxes . In national accounts definitions:
Disposable income
Disposable income can be spent on essential or nonessential items. Alternatively, it can also be saved. It is whatever income is left after taxes.
Personal income - personal current taxes = disposable personal income
This can be restated as: consumption expenditure + savings = disposable income
For the purposes of calculating the amount of income subject to garnishment, United States federal law defines disposable income as an individual's compensation (including salary, overtime, bonuses, commission, and paid leave) after the deduction of health insurance premiums and any amounts required to be deducted by law. Amounts required to be deducted by law include federal, state, and local taxes, state unemployment and disability taxes, social security taxes, and other garnishments or levies, but does not include such deductions as voluntary retirement contributions and transportation deductions.
Discretionary income is disposable income minus all payments that are necessary to meet current bills. It is total personal income after subtracting taxes and typical expenses (such as rent or mortgage, utilities, insurance, medical fees, transportation, property maintenance, child support, food and sundries, etc.) needed to maintain a certain standard of living. In other words, it is the amount of an individual's income available for spending after the essentials (such as food, clothing, and shelter) have been taken care of.
Discretionary income = Gross income - taxes - all compelled payments (bills)
Disposable income is often incorrectly used to denote discretionary income. The meaning should therefore be interpreted from context. Commonly, disposable income is the amount of "play money" left to spend or save.