MarketWatch
Is NIIT the same as the ‘millionaire tax’?
Q.: You mentioned in a column that there is a 3.8% “Net Investment Income Tax.” A.: Keith, no. The Net Investment Income Tax (NIIT) has nothing to do with having a million-dollar net worth and it comes into play long before income reaches a million. The NIIT is triggered once Modified Adjusted Gross Income (MAGI) reaches $200,000 for a single filer, $250,000 for a joint filer, $125,000 for a married person filing separately.