After-Tax Income

The amount of money that an individual or company has left over after all federal, state and withholding taxes have been deducted from taxable income. After-tax income represents the amount of disposable income that a consumer or firm has to spend on future investments or on present consumption. 

Also known as "income after taxes".

Investopedia Says:
When analyzing or forecasting personal or corporate cash flows, it is important to use an estimated after-tax net cash flow. This is a more appropriate measure because after-tax cash flows are what the entity has available for consumption.

This is not to say that all investments are purchased with after tax income; some companies offer salary deferral retirement plans that deduct money on a pretax basis. The money will be taxed once the employee decides to withdraw the amount (such as for retirement). However, because most people have less income during their retirement years compared to their prime earning years, the amount of tax paid will be less.

Related Links:
Follow these simple steps to get you ready for April 15. 10 Steps To Tax Preparation
Paying your bills early or giving an extra donation now can help you come tax time. Cut Your Tax Bill
IRA assets can't be taxed twice - find out how to avoid paying the second time around. Avoiding Too Much Tax On Your Distributions
Take a trip through history to learn from some (in)famously frugal Scots. Save Money The Scottish Way