The net investment income tax (NIIT) is an additional 3.8% tax that kicks in if you have investment income and your MAGI exceeds $200,000 for single filers, $250,000 for those married filing ...

The 3.8% net investment income tax, which is added to the regular income tax, covers more than you might think.

If you don’t know what Net Investment Income Tax (NIIT) is, you’re not alone. This relatively new tax began a little over a decade ago but the number of taxpayers subject to the tax has increased.

Most states offer at least one tax break to retirees but some exempt multiple forms of retirement income and eight states have no income tax at all.