Net Investment Income Tax on Rental Property Sales: 3.8% Rule
Yes, the 3.8% net investment income tax (NIIT) usually applies when you sell a rental property. Under §1411, it is 3.8% of the lesser of your net investment income or your modified AGI above $250,000 (married filing jointly), $200,000 (single or head of household) or $125,000 (married filing separately). For a passive rental, the whole gain counts as net investment income, including depreciation recapture. The main ways out are qualifying for the real estate professional safe harbor, freeing suspended passive losses, or spreading the gain so less of it sits above the threshold.
How the NIIT works
The tax is simple in structure and easy to underestimate.
- Rate: 3.8%.
- Base: the lesser of (a) net investment income or (b) modified AGI over the threshold.
- Thresholds: $250,000 joint, $200,000 single or head of household, $125,000 married filing separately (confirmed in the Form 8960 instructions).
- Not indexed. The thresholds are set in §1411(b) and do not adjust for inflation, so more sellers cross them every year.
- Form: Form 8960, Net Investment Income Tax. See also IRS Topic 559.
Because the base is the lesser of the two numbers, a large one-year gain often pushes modified AGI far over the threshold, and most of the gain gets the tax.
What counts as net investment income on a rental sale
For an owner who is not a qualifying real estate professional, rental real estate is a passive activity, and gain on selling it is net investment income. That includes every layer of the gain:
| Part of the gain | Income tax rate | NIIT? |
|---|---|---|
| Ordinary recapture (§1245 on cost-seg 5- and 7-year parts and equipment; §1250(a) on bonus taken on 15-year land improvements) | Ordinary | Yes, if passive |
| Unrecaptured §1250 gain | Up to 25% | Yes, if passive |
| Remaining long-term gain | 0/15/20% | Yes, if passive |
| Interest on a seller-financed note | Ordinary | Yes |
| Gain excluded under §121 (former home) | Excluded | No |
So a top-bracket seller's federal rate on the building's depreciation layer can reach 28.8% (25% plus 3.8%), and 23.8% on the rest of the gain. The depreciation recapture guide explains each layer.
Income that is excluded from gross income, such as gain excluded under the home sale exclusion, is not net investment income. That matters when you sell a former residence that became a rental; see selling a rental that was your primary residence.
Worked example: a passive rental sale
Simple example. A married couple filing jointly has $180,000 of modified AGI from pensions and IRA withdrawals, none of it investment income. They sell a rental they have owned for years and realize a $400,000 gain. They are not real estate professionals.
- Modified AGI: $180,000 + $400,000 = $580,000
- Excess over $250,000: $330,000
- Net investment income: $400,000
- NIIT: 3.8% x the lesser of $330,000 or $400,000 = $12,540
This is on top of regular income tax. Their pension income alone does not trigger the tax. The sale does.
Passive losses reduce it
Suspended passive losses freed by a full taxable sale (§469(g)) reduce net investment income in the year they are allowed (Reg. §1.1411-4(g)(9)). They also lower modified AGI, so they cut both halves of the "lesser of" test.
Simple example, continued. Same couple, but the sale frees $100,000 of suspended passive losses from the property. Net investment income drops to $300,000 and modified AGI to $480,000. The excess over $250,000 is $230,000, so NIIT is 3.8% x $230,000 = $8,740, a savings of $3,800.
One limit: net investment income deductions that exceed investment income in a year do not carry to other years (Reg. §1.1411-4(f)(1)(ii)). Losses help only in the year they are used. See suspended passive losses when you sell.
Real estate professionals: the 500-hour safe harbor
Real estate professional status (REPS) under §469(c)(7) makes rental activity nonpassive if you also materially participate. For the NIIT, there is a specific safe harbor in Reg. §1.1411-4(g)(7). If you are a real estate professional and you participate in the rental activity for more than 500 hours in the year, or did so in any 5 of the 10 years before, then:
- the rental income is deemed derived in the ordinary course of a trade or business, and
- gain on selling property used in that rental activity is treated the same way.
If the activity is also nonpassive, that income and gain are excluded from net investment income. Participation that counts toward material participation counts toward the 500 hours, including a spouse's hours. Failing the safe harbor does not rule out proving trade-or-business status another way (Reg. §1.1411-4(g)(7)(iii)).
Timing matters. Whether the gain is passive is set in the year of the sale, and substantially appreciated property (value over 120% of adjusted basis) that was used in a nonpassive activity within the 24 months before the sale contract, or was not passive for at least 20% of your holding period, is treated as nonpassive (Reg. §1.469-2(c)(2)(iii)). NIIT follows that year-of-sale character. See real estate professional status and material participation.
California does not follow the federal real estate professional rule (R&TC §17561(a)), but California has no NIIT, so this is a federal-only issue.
Installment sales: spreading the gain under the threshold
An installment sale does not change the character of the gain for NIIT. Reg. §1.1411-4(d), Example 2 says §453 governs the timing of the gain but not its character, and whether the gain is excluded is decided in the year of sale. What the installment method changes is how much modified AGI you have each year.
Simple example, continued. Instead of taking the $400,000 gain in one year, the couple sells on a note and reports $80,000 of gain a year for five years. Ignoring interest, their modified AGI is $260,000 each year, just $10,000 over the threshold. NIIT is 3.8% x $10,000 = $380 a year, $1,900 in total instead of $12,540.
The catch: interest on the note is also net investment income, and it raises modified AGI. With $20,000 of interest in the first year, that year's NIIT would be 3.8% x $30,000 = $1,140. Still well below the one-year result, but not zero. You can model the payments in the free installment sale calculator, and the ISC installment sale guide explains the mechanics.
A 1031 exchange defers the NIIT along with the gain, and boot you receive is taxed, including NIIT if passive.
Reporting on Form 8960
For a rental sale, the key lines are:
- Line 4a: rental income from Schedule E, with line 4b adjusting out nonpassive rental income from a real estate professional whose rental rises to a §162 trade or business.
- Line 5a: net gain from the disposition of property, with line 5b removing gain from property held in a trade or business not subject to NIIT.
- Line 17: the individual NIIT.
Line 5b does not remove gain on substantially appreciated property recharacterized as portfolio income under the passive rules, so the 24-month rule above can bring gain back in.
Common NIIT mistakes on rental sales
- Assuming recapture is exempt. On a passive rental, it is net investment income like the rest of the gain.
- Forgetting the thresholds are not indexed. $250,000 joint in 2013 is still $250,000.
- Claiming REPS without the hours log. The 500-hour safe harbor needs records.
- Ignoring note interest. It is net investment income every year.
- Counting on unused losses next year. Excess NII deductions do not carry over.
- Assuming a state version exists. It is federal only.
Bottom line
On a passive rental, the 3.8% net investment income tax applies to the whole gain, recapture included, once your modified AGI passes $250,000 (joint). You can reduce it by freeing suspended passive losses in the sale year, qualifying for the real estate professional 500-hour safe harbor, or spreading the gain with an installment note so less income sits above the threshold each year. The free book shows how sellers time the gain against passive losses and brackets.
Questions to ask your CPA
- Is my rental passive for the year of sale, and was it passive for the 24 months before the contract?
- Do I qualify for the real estate professional safe harbor in Reg. §1.1411-4(g)(7)?
- How much suspended passive loss will this sale free, and how much NIIT does it save?
- What will my modified AGI be each year if I sell on a note, including interest?
- Will any part of my gain be excluded under §121?
- How do the Form 8960 lines 4b and 5b adjustments apply to my facts?
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Educational only, not tax, legal or investment advice. Examples are illustrative. Have your CPA or tax attorney review your facts before you act. Hans Goldstein is a licensed insurance agent (CA Insurance License #4273294) and is not a CPA or attorney. He is paid a commission only if a structured installment sale is funded; seller financing pays him nothing. Disclosures.