Net Investment Income Tax Guide for High-Income Investors (2026)
Calculate net investment income tax: 3.8% NIIT rate, income thresholds, investment income definition, and tax planning for high-income taxpayers.
Summary
NIIT applies 3.8% tax to high-income investment income. This guide explains thresholds, income calculation, and planning strategies.
Key Steps
- 1Check income threshold: $200K single, $250K married filing jointly triggers NIIT.
- 2Identify investment income: dividends, interest, capital gains, rental, royalties.
- 3Calculate NIIT liability: 3.8% of lesser of NII or excess MAGI over threshold.
- 4Plan income timing: defer investment income, harvest losses, Roth conversions.
- 5Track rental income: rental income subject to NIIT unless material participation.