Tax Strategy · 6 min read · 2026-02-10
The 9-step NIIT planning.
NIIT is the silent surcharge on investment income for higher earners. Nine moves manage it.
3.8% adds up across decades.
The Net Investment Income Tax adds 3.8 percentage points to the federal tax on investment income (interest, dividends, capital gains, rents, royalties) for taxpayers above MAGI thresholds. The surtax is invisible to many because it's calculated separately, but it accumulates to thousands of dollars annually for higher earners.
The nine indicators
The nine moves of NIIT planning.
Each is a specific action to reduce NIIT-applicable income or shift it below thresholds. The composite controls the surtax.
MAGI threshold awareness
Threshold: $200K single / $250K MFJ
NIIT applies above these MAGI thresholds. Below, no NIIT; above, NIIT applies to lesser of net investment income or excess MAGI.
Capital loss harvesting offsets gains
Pattern: net investment income calculation
Tax-loss harvesting reduces net investment income. Each $1 of harvested loss reduces NIIT by $0.038.
Roth conversions push MAGI up
Pattern: temporary spike
Roth conversions can spike MAGI above NIIT thresholds. The conversion year may produce NIIT on previously-untaxed investment income.
Retirement contributions reduce MAGI
Pattern: 401k, HSA, traditional IRA
Pre-tax retirement contributions reduce MAGI. Below threshold means no NIIT on investment income.
Asset location for taxable accounts
Pattern: tax-efficient choices
Hold tax-efficient assets (index funds, muni bonds) in taxable. Tax-inefficient assets (REITs, taxable bonds) in IRA.
Charitable contributions of appreciated securities
Pattern: avoid gain
Donating appreciated securities to charity avoids the gain — both income tax and NIIT. Combined benefit.
QCDs for retirees 70½+
Pattern: outside MAGI
QCDs reduce MAGI. They count toward RMD without adding to AGI. Multiple-benefit strategy.
1031 exchanges for real estate
Pattern: defer gain
Like-kind exchanges defer real estate capital gains, including NIIT-eligible portion.
Active vs passive income classification
Pattern: material participation
Active business income is excluded from NIIT. Passive activity income is included. Material participation status matters.
What NIIT actually is
Section 1411 of the Internal Revenue Code, enacted as part of the 2010 Affordable Care Act, imposes a 3.8 percent tax on net investment income for taxpayers above specific MAGI thresholds. The thresholds — $200,000 single, $250,000 married filing jointly — have not been indexed since enactment, meaning more taxpayers cross them each year.
The tax applies to the lesser of net investment income or excess MAGI above the threshold. Calculation is on Form 8960 attached to the regular tax return. Most tax software handles it automatically, but the planning to minimize it requires deliberate income management.
What counts as net investment income
Net investment income includes: interest, dividends (qualified and non-qualified), net capital gains, rental income (subject to material participation rules), royalty income, and income from passive trade or business activities. It excludes: wages, self-employment income, distributions from qualified retirement plans (IRA, 401k), Social Security, and active business income.
The exclusion of retirement distributions is meaningful. Roth IRA withdrawals, traditional IRA RMDs, and 401(k) distributions are all outside NIIT. The tax targets investment income held in taxable accounts. This is why asset location and tax-advantaged-account utilization remain valuable tools.
MAGI bracket management
The simplest NIIT-minimization is to keep MAGI below the threshold. For households near the threshold, modest tactical moves — maximizing 401(k) contributions, HSA contributions, traditional IRA contributions when deductible — can keep MAGI below NIIT triggers.
Above the threshold, the strategy shifts to managing investment income itself: tax-loss harvesting, holding period management, asset location, and charitable structures. The surtax is unavoidable for very-high-income households but can be reduced meaningfully through deliberate planning.
Roth conversions and the year they happen
Roth conversions add to MAGI and can push taxpayers above NIIT thresholds in the conversion year. The conversion itself is not subject to NIIT (retirement plan distribution exclusion), but the higher MAGI increases the NIIT-applicable amount on other investment income.
The discipline is to size conversions with NIIT in mind. Conversions sized to fit within the lower bracket also fit below NIIT thresholds, providing a coordinated tax efficiency. Conversions large enough to exceed NIIT thresholds add the surtax to the regular conversion tax cost.
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Common questions
Questions.
Are Social Security benefits subject to NIIT?
No — Social Security benefits are not investment income, regardless of taxability under Section 86.
What about real estate rental income?
Generally subject to NIIT unless the taxpayer is a real estate professional under §469(c)(7) and materially participates.
Are muni bonds exempt from NIIT?
Tax-exempt municipal bond interest is not investment income for NIIT purposes. But the muni interest is still in MAGI for the threshold.
Will NIIT thresholds be indexed?
Not under current law. Thresholds have been frozen since 2013, increasing the affected population each year.
Can I deduct NIIT?
No — NIIT is a federal income tax; not separately deductible.
Does NIIT apply to estates and trusts?
Yes, with much lower threshold (top tax bracket). Estate and trust planning needs to consider NIIT.
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