The 3.8% Net Investment Income Tax on Real Estate

Most investors price a property sale at the long-term capital-gains rate and stop there. For higher earners that math is short by 3.8 points. A second federal layer, the net investment income tax, sits on top of the headline rate and turns a 20% federal gain into 23.8%. The same surtax reaches rental income, royalties, and REIT dividends. Its income thresholds have been frozen since 2013, so each year of inflation drags more sellers into it. This article walks through who owes the NIIT in 2026, what income counts, the narrow real estate professional exception, and how a 1031 exchange or DST changes the picture.

What the NIIT actually is

Congress enacted the net investment income tax in 2013 under Section 1411 of the tax code as part of the Affordable Care Act. People sometimes call it the Medicare surtax, though the money does not flow into the Medicare trust funds the way the payroll Medicare tax does. The mechanics are what matter. It is a flat 3.8% charge that sits on top of the regular income tax and the capital-gains tax, computed on Form 8960 and carried onto your Form 1040.

The single most misunderstood point is that the NIIT is not 3.8% of all your investment income. It is 3.8% of the lesser of two numbers. The first number is your net investment income for the year. The second is the amount by which your modified adjusted gross income exceeds the threshold for your filing status. You pay the surtax on whichever of those two figures is smaller.

That structure has a practical edge. A taxpayer whose MAGI barely crosses the threshold pays the surtax on only the small slice above the line, even if their investment income is large. A taxpayer with MAGI far above the threshold pays on the full amount of their net investment income. A one-time event, the sale of an appreciated rental, often does both at once. The gain lifts MAGI hundreds of thousands of dollars past the threshold and supplies a big block of net investment income, so the lesser-of test usually resolves to the entire gain.

A short example fixes the idea. Suppose a married couple has $230,000 of MAGI from salary and modest interest, then sells a rental and books a $400,000 long-term gain. The gain pushes MAGI to $630,000, which is $380,000 over the $250,000 joint threshold. Their net investment income for the year is roughly the $400,000 gain plus the interest. The surtax applies to the lesser figure, the $380,000 excess MAGI in this case, at 3.8%, which is about $14,440 of NIIT on top of the capital-gains tax. The numbers here are illustrative, not a projection for any real return, but the shape holds.

Who owes it and the frozen thresholds

The MAGI thresholds that switch the NIIT on are written into the statute and, unlike most tax figures, are not indexed for inflation. They read the same in 2026 as they did when the tax began in 2013. The table below shows them by filing status.

Filing status	MAGI threshold	Inflation-indexed?
Single	$200,000	No, frozen since 2013
Head of household	$200,000	No, frozen since 2013
Married filing jointly	$250,000	No, frozen since 2013
Qualifying surviving spouse	$250,000	No, frozen since 2013
Married filing separately	$125,000	No, frozen since 2013

Thresholds compare against modified adjusted gross income, not taxable income. Figures are current for the 2026 tax year and apply per return.

MAGI is not the same as taxable income. For most taxpayers, modified adjusted gross income equals adjusted gross income, the bottom line of the front page of the 1040, with a few foreign-income add-backs that rarely apply to domestic real estate investors. The thresholds compare against this MAGI figure, before the standard or itemized deduction. That distinction matters, because a deduction that lowers taxable income does not always lower MAGI, and only MAGI moves you across the NIIT line.

Because the thresholds never rise, ordinary wage growth and inflation push more households over them every year. That is a quiet form of bracket creep. A two-income professional household can sit near the $250,000 joint line in a normal year and tip over it the moment a rental or a brokerage account produces a gain. For a real estate investor, a single profitable sale almost guarantees the surtax for that tax year unless the gain is deferred or restructured. The married-filing-separately threshold of $125,000 is worth flagging, because it is exactly half the joint figure and catches separately filing spouses fast.

What counts as net investment income, and what does not

Net investment income is a defined category, not a catch-all for everything that earns a return. The cleanest way to hold it is as a two-column list. The table below sorts the common items a real estate investor will recognize.

Counts as net investment income	Does not count
Taxable interest	Wages and salary
Dividends, including REIT dividends	Self-employment income
Capital gains, including gain on the sale of investment real estate	Active trade-or-business income
Depreciation recapture, as part of the gain on a rental sale	Tax-exempt municipal bond interest
Net passive rental income	Distributions from qualified retirement plans and IRAs
Royalty income from mineral and similar interests	Gain excluded under §121 on a primary residence
Non-qualified annuity income	Social Security benefits
Income from passive businesses you do not materially participate in	Income from a non-passive trade or business

General categories for orientation. The classification of a specific item depends on your facts and your participation in the activity.

A few of these deserve a closer look because they trip up real estate sellers. Depreciation recapture is part of the gain, not a separate exempt bucket. When you sell a rental, the portion of the gain attributable to depreciation you claimed is taxed as unrecaptured Section 1250 gain at a federal rate of up to 25%. That recapture is still investment income, so the 3.8% surtax can land on it as well. The interaction is covered in more depth in our piece on depreciation recapture on real estate.

The §121 home-sale exclusion is a genuine escape hatch, within its limits. Gain you exclude under §121, up to $250,000 single or $500,000 joint on a qualifying primary residence, never enters gross income, so it never reaches the NIIT either. Gain above the exclusion does. That is why a long-held primary residence that has appreciated past the exclusion can still produce a NIIT bill on the excess. The mechanics of the underlying gain are in our overview of how capital gains tax on real estate works.

On the excluded side of the ledger, note that active business income and self-employment income sit outside the NIIT. They are not free of surtax, they simply face the additional Medicare tax of 0.9% on earned income instead. A given dollar is hit by one regime or the other, not both. That line between passive investment income and active business income is the hinge the real estate professional exception turns on.

The real estate professional exception

Rental income is passive by default, and passive income is squarely inside the NIIT. The main way to move rental income and rental gain out of net investment income is to make it non-passive, because non-passive income earned in the ordinary course of a trade or business is excluded from the surtax. That is where the real estate professional status under Section 469 comes in.

Qualifying takes two tests, both met for the year, and both are demanding:

• More than 750 hours of personal services in real property trades or businesses in which you materially participate.
• More than half of all the personal-service time you spend on any trade or business during the year must be in those real property trades.

Clearing the 750-hour bar is only the entry ticket. You also have to materially participate in the specific rental activities, and the rental has to rise to the level of a trade or business rather than a passive holding. A full-time professional in another field will struggle to satisfy the more-than-half test, because their main job already consumes most of their service hours. A retiree with a brokerage account and a couple of triple-net leases will struggle with the trade-or-business and material-participation pieces. The status is realistic for full-time operators, brokers, developers, and property managers, and it is documentation-heavy, hours logs and contemporaneous records, because it is a frequent audit target.

The honest takeaway for most readers of this article is that they will not qualify. If you are a passive investor holding rentals or DST interests alongside a W-2 job, plan as though your rental income and gain are inside the NIIT, and treat the real estate professional route as a question for your CPA rather than an assumption. For a fuller treatment of where the passive line sits, see active versus passive real estate investing.

How a 1031 exchange interacts with the NIIT

The NIIT only reaches gain you actually recognize. That single fact is what makes deferral the most powerful lever an investor has over the surtax. A 1031 exchange defers the capital gain on the sale of investment real estate into the replacement property, and because the gain is not recognized, there is no net investment income from that sale to tax. The 3.8% surtax rides along with the deferred gain. You do not pay it in the year of sale.

This matters most for the large one-time gain, which is precisely the event that would otherwise blow MAGI far past the threshold and expose the whole gain to the surtax. By deferring recognition, a 1031 exchange keeps that spike off the current year's return. The deferred NIIT becomes a future liability that only crystallizes if and when you sell the replacement property in a taxable sale. If you keep exchanging, you keep deferring.

The endgame is the part investors underweight. A step-up in basis at death can erase the deferred liability altogether. When appreciated property passes to heirs, the basis generally resets to fair market value as of the date of death, wiping out the unrealized gain. No recognized gain means no capital-gains tax and no NIIT on that appreciation. The phrase "swap till you drop" describes the strategy: defer through exchanges across a lifetime, then let the step-up clear the slate. None of this is guaranteed, tax law can change and a botched exchange recognizes gain, but the structure is well established.

Deferral is not the only lever. The other side of the lesser-of test is MAGI itself. Spreading income across years, timing a sale into a lower-income year, harvesting capital losses, and making deductible retirement contributions can all keep MAGI closer to the threshold and shrink the slice exposed to the surtax. For how deferral stacks against other approaches, see our comparison of tax deferral strategies and the practical guide to reducing capital gains tax on investment property.

How a DST interacts with the NIIT

A Delaware Statutory Trust is a passive way to complete a 1031 exchange. Instead of buying and managing a replacement property yourself, you exchange into a fractional beneficial interest in a trust that holds institutional real estate. The exchange into the DST defers the original gain exactly as a direct 1031 would, so the NIIT on the relinquished property is deferred along with it.

The treatment of the DST itself, once you hold it, is the part to be clear-eyed about. DST income and gain are generally investment income subject to the NIIT. Because a DST is a passive investment by design, the beneficiary does not materially participate, so the rental income the DST distributes and the eventual gain when the trust's property is sold are net investment income for an accredited passive investor whose MAGI is over the threshold. A DST does not convert passive real estate into non-passive income, and it cannot make you a real estate professional. It defers the original gain, it does not exempt the new income stream from the surtax.

That is not a knock on the structure. It simply means the value of a DST against the NIIT lies in the deferral it preserves, the same as a direct exchange, rather than in any ongoing exemption. The eventual exit from a DST can itself be rolled into another 1031 exchange or, in some programs, a 721 exchange into a REIT, which continues the deferral and keeps the surtax at bay. And DSTs are speculative, illiquid securities sold only to verified accredited investors through a private placement memorandum. They can lose principal. The tax mechanics never change that risk profile.

Putting the calculation together

It helps to see the whole stack on a single dollar of gain. For a top-bracket investor selling appreciated investment real estate, the federal layers run roughly as follows. The long-term capital-gains rate of 20% applies to the appreciation. The unrecaptured Section 1250 gain from prior depreciation is taxed at up to 25%. The NIIT of 3.8% then sits on top of both, to the extent the lesser-of test exposes the gain. State income tax stacks on after that. The headline 20% an investor remembers can become 23.8% federally before a state ever weighs in, and higher still once recapture is in the mix.

Two refinements keep the estimate honest. First, the surtax applies to the lesser of net investment income or excess MAGI, so a seller whose MAGI only barely crosses the threshold pays far less surtax than the gain alone would suggest. Second, the NIIT is computed on the year's total, so other investment income, interest, dividends, passive rental income, adds to the base and can pull more of the threshold gap into the taxed amount. Running an actual sale through these layers, rather than eyeballing a single rate, is the only way to size the real number, and it is a calculation to do with your CPA before you sign.

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