Reducing Your Exposure to the Net Investment Income Tax

May 20 2026 | Back to Blog List

The Net Investment Income Tax (NIIT) has been around for more than a decade, but we're answering more questions about it these days.

This 3.8% federal surtax applies to certain investment income when a taxpayer's Modified Adjusted Gross Income (MAGI) exceeds specific thresholds. Because those thresholds aren't indexed for inflation, more households may find themselves exposed to the tax over time.

For many high-income investors, NIIT is treated as a fact of life—an accepted cost of a successful investment strategy—but for households crossing those thresholds for the first time, it can be an unpleasant surprise at tax time.

That's why NIIT deserves more attention than it typically gets. The surtax can rarely be eliminated entirely, but it can often be reduced—sometimes meaningfully—through disciplined planning and coordination.

Here's what you need to know about NIIT, and the situations where planning around it tends to make the biggest difference.

What is the Net Investment Income Tax?

The Net Investment Income Tax was enacted as part of the Affordable Care Act and took effect in 2013. It's a 3.8% surtax on certain investment income for taxpayers whose Modified Adjusted Gross Income (MAGI) exceeds specific thresholds. For most taxpayers, those thresholds are:

• $250,000 — Married Filing Jointly
• $200,000 — Single or Head of Household
• $125,000 — Married Filing Separately

As we noted earlier, these thresholds are not indexed for inflation, meaning more households may become exposed to NIIT over time.

The formula for NIIT itself is straightforward. This surtax applies to 3.8% of the lesser of:

• Net investment income, or
• MAGI above the applicable threshold

That word lesser is the most important part of the formula, because it means there are two strategic levers, not one: lowering MAGI and reducing net investment income. Which lever matters most depends on the situation; the right planning for many investors often involves coordinating both.

What Counts as Investment Income (And What Doesn't)?

Understanding what does and doesn't count as net investment income is the foundation of any NIIT planning conversation. Many NIIT planning strategies start with this distinction: what counts toward net investment income, what only affects MAGI, and what may avoid both.

Generally counts as net investment income:

• Interest from taxable bonds, CDs, and bank accounts
• Dividends
• Capital gains
• Rental and royalty income from passive sources
• Non-qualified annuity distributions

Generally doesn't count:

• Wages and active business income
• Distributions from IRAs and qualified retirement plans
• Social Security benefits
• Tax-exempt interest from municipal bonds
• Gain on a primary home sale within the standard exclusion ($250,000 for single filers / $500,000 for married filing jointly)

Note that some items that aren't counted as net investment income, like an IRA distribution, can still raise MAGI. And a higher MAGI can pull other investment income into NIIT exposure. The two sides of the formula don't move independently. That's where coordination across the tax return and the portfolio starts to matter.

Three Situations Where NIIT Shows Up

The 3.8% surtax often shows up in the following client situations, and the planning response looks different in each one.

Situation 1: The retiree with significant cash holdings

A retired couple keeps a meaningful share of their portfolio in CDs and bank savings for liquidity, stability, or simply because that's where the assets have lived for years. Each year, the interest flows through as taxable income. They pay ordinary income tax on it; if their MAGI is high enough, the 3.8% surtax can stack on top.

For a married couple filing jointly with $500,000 in CDs earning around 4.5%, that generates about $22,500 in annual interest. If their MAGI is far enough above the $250,000 threshold, that interest may be fully exposed to NIIT, adding roughly $855 per year to their tax bill, on top of the ordinary income tax already owed. The dollar amount may be modest in any single year, but over a decade, the same drag adds up—in this case, to more than $8,500 on the same dollars, doing the same work.

The planning response here usually isn't dramatic. Reallocating a portion of that fixed-income exposure into tax-exempt municipal bonds, when appropriate, may reduce the interest that's subject to NIIT.

This is also where tax-equivalent yield matters: a 4.5% taxable yield may look closer to a 2.9% after federal income tax and NIIT for a taxpayer in the 32% marginal bracket. Repositioning interest-generating assets inside tax-deferred accounts can also shift the same income out of the surtax base entirely. Neither move requires changing the underlying allocation. They simply change where the income lives.

Situation 2: The investor with a one-time liquidity event

For investors facing a business sale, a real estate disposition, or the unwinding of a large stock position, MAGI can spike well above the threshold in a single year. In that case, a meaningful portion of the gain may be subject to NIIT on top of the long-term capital gains rate.

Consider a business owner who sells a stake for a $2 million long-term capital gain. Depending on the rest of their tax picture, that gain may be subject to the 20% federal long-term capital gains rate, state taxes, and NIIT. If the full gain is exposed to the 3.8% surtax, NIIT alone could add roughly $76,000 in a single tax year.

This is where the dollar leverage of planning tends to be highest, and where multi-year coordination matters most. An installment sale can spread gain recognition over time. A §1031 exchange may defer recognition on eligible real estate. A charitable remainder trust may help manage a large concentrated gain by deferring recognition of income from assets transferred to the trust while creating a current charitable deduction. Even simply timing the event into a lower-income year can change the outcome materially.

None of these tools is right in every situation. But the difference between reacting to a liquidity event after the fact and planning for it across multiple years can be significant.

Situation 3: The high-earner with a taxable portfolio

For the working professional or business owner whose MAGI sits comfortably above the threshold each year, NIIT isn't an episodic issue—it's a recurring tax on portfolio income.

The most useful planning lever here tends to be asset location. Interest-generating assets like taxable bonds, REITs, and high-turnover funds may be more efficiently held inside tax-deferred accounts, where their income doesn't enter the NIIT base. Taxable accounts may be better suited for assets that generate less recurring income, such as broad-market index funds, individual equities held long-term, and tax-exempt municipal bonds.

Asset location doesn't change the underlying asset allocation, it simply changes the structure around it. For investors who are consistently above the threshold, that structural choice may reduce years of recurring NIIT exposure.

(Learn more about asset location in our Insights post about tax diversification.)

Other Strategic Levers Worth Knowing About

Beyond the situation-specific responses above, several broader strategies may help reduce NIIT exposure:

Lowering MAGI can pull income back below the threshold or reduce the surtax base. Common approaches include maximizing pre-tax retirement contributions, contributing to a Health Savings Account if eligible, and, for clients age 70½ or older, using Qualified Charitable Distributions to make charitable donations directly from an IRA without increasing MAGI.

Lowering net investment income can reduce the surtax base directly. Tax-loss harvesting, holding tax-exempt municipal bonds in the taxable account, donating appreciated securities—often through a donor-advised fund—rather than selling them, and being deliberate about when realized gains are taken across years can each contribute.

Sequencing matters more than any single tactic. Roth conversions, large one-time sales, and even small year-end decisions when MAGI is hovering near the threshold all work better when modeled across multiple years rather than addressed in isolation. That same coordination can matter for other income-sensitive costs, including Medicare's IRMAA surcharges.

The Cedar Point Perspective

For investors who are consistently and well above the income thresholds, NIIT generally can't be eliminated. But the gap between paying NIIT thoughtfully and paying NIIT by default is real. Sometimes it's measured in hundreds of dollars a year; in the case of a significant one-time liquidity event, it can be much more.

Closing that gap isn't about finding the right single strategy; it's a matter of looking at the tax return, the portfolio, and the long-term plan in the same conversation, then identifying the moves that only become visible when all three are on the table at once.

For the investors we serve, this kind of coordination is central to the planning process. If you're looking for that in a financial partner, let's start the conversation.

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