Tax Concepts

Net Investment Income Tax (NIIT)

Additional 3.8% tax on net investment income for high earners.

Reviewed 9 August 2026 by Keiron Brown, Founder & Editor, CalculateRealEstateROI · Educational estimates only — not investment, financial, tax, or legal advice

Plain-English explanation

Stacks on top of capital gains. Thresholds: $200k single, $250k MFJ.

Examples

$50k rental income × 3.8% NIIT = $1,900 additional tax.

Common mistakes

Forgetting NIIT in marginal-rate calculations.

Net Investment Income Tax (NIIT)

Plain-English explanation

Examples

Common mistakes

Related questions