The Net Investment Income Tax under IRC §1411 imposes a 3.8% surtax on the lesser of net investment income (NII) or the amount by which modified adjusted gross income (MAGI) exceeds threshold amounts. Enacted as part of the Affordable Care Act and effective from tax year 2013, the rate has never changed. Critically, the thresholds have never been indexed for inflation: $200,000 single / HOH, $250,000 MFJ / qualifying surviving spouse, $125,000 MFS - identical to the 2013 starting figures. Trusts and estates face a much lower threshold ($16,000 for 2026, the top §1(e) bracket) which sweeps most non-grantor trusts into NIIT. Form 8960 computes the tax. Material participation under §469 and real estate professional status under §469(c)(7) remain the dominant planning tools. On August 31, 2026, the Federal Circuit held in Bruyea and Christensen that foreign tax credits under the US-Canada and US-France treaties cannot offset NIIT.
Rate: 3.8% - unchanged since 2013 enactment.
MAGI thresholds (individuals - NOT indexed): $200,000 single / HOH, $250,000 MFJ / QSS, $125,000 MFS.
Trust / estate threshold (indexed): $16,000 for 2026 - the top bracket under §1(e). Top bracket inflation drives the trust NIIT threshold upward annually.
Computation: 3.8% × lesser of (a) NII or (b) MAGI excess over threshold.
Form: Form 8960 attached to Form 1040, 1041, or 1040-NR (only if joint election with US spouse).
Bracket creep: Because thresholds are not indexed, more taxpayers are caught every year. The 2026 single-filer threshold ($200,000) is below the top of the 24% bracket - putting NIIT in regular middle-upper-class territory.
NII under §1411(c)(1) is gross income from three categories MINUS allocable deductions. The categories are mutually exclusive in design but overlap in application.
| Category | Description | Authority |
|---|---|---|
| (A)(i) Interest, dividends, annuities, royalties, rents | Investment-type income not derived in a trade or business (other than passive T/B - see (c)(2)) | §1411(c)(1)(A)(i) |
| (A)(ii) Other gross income from a §1411 trade or business | Income from §469 passive T/B OR trade or business of trading in financial instruments / commodities | §1411(c)(1)(A)(ii) / §1411(c)(2) |
| (A)(iii) Net gain from disposition of property | Net gains other than those attributable to non-§1411 trade or business property | §1411(c)(1)(A)(iii) |
| Less allocable deductions under §1411(c)(1)(B) | Investment expenses, state income tax allocable to NII, investment interest expense, miscellaneous deductions (where applicable) | §1411(c)(1)(B) |
| Income Item | NII? |
|---|---|
| Interest (taxable - bank, bond, note) | YES |
| Tax-exempt municipal bond interest | NO - excluded from MAGI and from NII |
| Dividends (qualified and ordinary) | YES |
| Capital gains (short-term, long-term) | YES (subject to §1411(c)(1)(A)(iii) trade or business exception) |
| Annuity income (non-retirement) | YES |
| Royalties (not from active T/B) | YES |
| Rental income (passive activity) | YES (most rentals are passive under §469) |
| Rental income (real estate professional under §469(c)(7), materially participating) | NO if it rises to a §162 T/B level and material participation exists |
| Income from passive T/B (Schedule K-1) | YES (§1411(c)(2)) |
| Income from nonpassive T/B (materially participating) | NO |
| Gain on sale of materially-participating S-corp stock | NO to extent of T/B operations; specific §1411(c)(4) rules apply (proposed Reg §1.1411-7) |
| Gain on sale of rental property held in passive T/B | YES |
| Gain on sale of principal residence | Excluded if §121 applies; only excess over §121 exclusion ($250K single / $500K MFJ) is NII |
| Wages and self-employment income | NO (§1411(c)(6) - earned income excluded because already subject to Medicare under §1401(b)) |
| Distributions from IRAs, 401(k), pensions | NO - retirement plan distributions excluded under §1411(c)(5) |
| Social Security benefits | NO - excluded; taxable portion counts in MAGI but not in NII |
| Unemployment compensation, alimony | NO - not investment income |
| CFC Subpart F or NCTI inclusions | NO at inclusion by default (later PTEP distributions are NII dividends); YES at inclusion if a §1.1411-10(g) election is made |
| PFIC inclusions | QEF inclusions: same default and §1.1411-10(g) election as CFCs. Section 1296 mark-to-market inclusions: YES, as net gain when included (Reg §1.1411-10(c)(2)(ii)) |
| K-1 from trading partnership | YES - trading in financial instruments / commodities is §1411 T/B under §1411(c)(2)(B) |
Facts: Single Client, 2026. Wages $180,000. Dividends $40,000. Capital gains $30,000. Bank interest $5,000. Rental loss (passive) $(10,000). MAGI = $245,000.
Step 1 - NII: Dividends $40,000 + capital gains $30,000 + interest $5,000 - passive rental loss $10,000 (deductible against passive income to extent of grouped passive income) = $65,000 NII.
Step 2 - MAGI excess over threshold: $245,000 - $200,000 = $45,000.
Step 3 - NIIT: 3.8% × LESSER of $65,000 NII or $45,000 MAGI excess = 3.8% × $45,000 = $1,710.
Reporting: Form 8960 Line 17 carries to Schedule 2 (Form 1040) Line 12. Total tax includes the $1,710 NIIT plus regular income tax on full $245,000 MAGI.
MAGI for §1411 purposes is regular AGI plus adjustments under §1411(d):
| NIIT MAGI Adjustment | Effect |
|---|---|
| Regular AGI (Form 1040 Line 11) | Starting point |
| Add: foreign earned income excluded under §911(a)(1) | FEIE-excluded amounts ARE counted in NIIT MAGI even though excluded from regular AGI |
| Less: deductions or exclusions disallowed under §911(d)(6) on the excluded amount | Housing cost exclusion under §911(a)(2) is NOT added back; only the §911(a)(1) exclusion (Form 2555 line 42), net of the related disallowed deductions (Form 2555 line 44), is added |
| Add: net excluded gain from certain CFCs / QEF PFICs (if §1.1411-10(g) NOT elected) | Adjusts MAGI for income deferred under default treatment |
| Less: adjustments related to §1.1411-10(g) election (if elected) | Avoids double-inclusion when election in effect |
| Tax-exempt municipal bond interest | NOT added back - excluded from MAGI |
| QBI deduction under §199A | NOT added back - deducted "below the line" |
| Standard deduction or itemized deductions | NOT added back - deducted "below the line" |
NII includes income from a "§1411 trade or business," defined under §1411(c)(2) as either (a) a §469 passive activity OR (b) a trade or business of trading in financial instruments or commodities. The first category captures most rental real estate and many K-1 sources; the second captures professional traders.
| Activity | Status | NIIT Treatment |
|---|---|---|
| Passive activity under §469 (material participation tests not met) | §1411 T/B | Net income / loss flows to NII |
| Nonpassive activity (material participation OR §469(c)(7) real estate professional with material participation) | NOT §1411 T/B | Net income / loss EXCLUDED from NII under §1411(c)(1)(A)(iii) |
| Trading in financial instruments / commodities (e.g., professional day trader) | §1411 T/B regardless of participation | Net trading gains flow to NII |
| Working interest in oil/gas without limited liability | NOT passive under §469(c)(3) | Income excluded from NII |
| Self-rental to one's own active business (§469 self-rental rule) | Recharacterized nonpassive for net income; remains passive for net loss | Asymmetric: income excluded from NII; loss included |
An activity is nonpassive under §469 (and outside §1411 T/B classification for that reason) if the taxpayer materially participates. Material participation is met by satisfying ANY ONE of seven tests under Reg §1.469-5T(a).
| Test | Standard |
|---|---|
| 1. 500 hours | Taxpayer participated in the activity for more than 500 hours during the year |
| 2. Substantially all participation | Taxpayer's participation constitutes substantially all participation in the activity (e.g., sole proprietor doing everything) |
| 3. 100 hours and no one more | Taxpayer participated more than 100 hours AND no other individual participated more |
| 4. 100+ hours significant participation activity aggregation | Sum of significant participation activities (each > 100 hours but not materially participating alone) exceeds 500 hours |
| 5. 5 of last 10 years | Taxpayer materially participated in the activity in any 5 of the prior 10 tax years |
| 6. Personal service activity prior years | For personal service activity, material participation in any 3 prior tax years |
| 7. Facts and circumstances 100+ hour test | Taxpayer participated on a regular, continuous, and substantial basis (100+ hour minimum implicit; supports facts-and-circumstances finding) |
Material participation is a facts question. The IRS scrutinizes hour logs heavily. Audit-defensible documentation includes:
| Documentation Best Practice |
|---|
| Contemporaneous time log with date, hours, specific tasks performed |
| Calendar entries supporting hour log |
| Emails, contracts, vendor correspondence dated to support activity periods |
| Travel records consistent with site visits / property inspections |
| Receipts for materials, supplies, services with dates |
| NO retrospective reconstruction; logs created after IRS inquiry are not credible (Hakkak v. Commissioner, T.C. Memo 2020-46 and similar cases) |
Real estate professionals can elect to treat rental real estate activities as nonpassive if both prongs are met. Once nonpassive, material participation in each rental activity must still be separately established for that rental's nonpassive treatment to apply to NIIT.
| Two-Prong Real Estate Professional Test |
|---|
| Prong 1: More than 50% of personal services performed by the taxpayer during the tax year are performed in real property trades or businesses in which the taxpayer materially participates |
| Prong 2: Taxpayer performs more than 750 hours of services during the tax year in real property trades or businesses in which the taxpayer materially participates |
| Real Property T/B (counts toward 50% and 750 hours) |
|---|
| Real property development |
| Real property redevelopment |
| Real property construction |
| Real property reconstruction |
| Real property acquisition |
| Real property conversion |
| Real property rental |
| Real property operation |
| Real property management |
| Real property leasing |
| Real property brokerage |
| Form 8960 Section | Lines | Content |
|---|---|---|
| Investment Income | 1-4c | Interest, dividends, annuities, royalties, rents; trade or business §1411 income; adjustments |
| Net Gain or Loss From Disposition of Property | 5a-5d | Net gain from disposition of property; adjustments for non-§1411 T/B |
| Adjustments to Investment Income (CFC / PFIC) | 6-7 | §1.1411-10(g) election adjustments for CFC and QEF inclusions |
| Total Investment Income | 8 | Sum of items 1-7 |
| Investment Expenses | 9a-9c | Investment interest expense (Form 4952); state income tax allocable; miscellaneous |
| Modifications to Investment Income | 10 | Additional modifications |
| Total Deductions and Modifications | 11 | Sum of 9a-10 |
| Net Investment Income | 12 | Line 8 minus Line 11 (cannot be less than zero) |
| Individuals: MAGI thresholds and calculation | 13-17 | MAGI; threshold; excess; tax (3.8% × lesser of NII or excess) |
| Estates and Trusts: alternative calculation | 18-21 | Different lines for trust/estate computation |
By default, NCTI / Subpart F or QEF inclusions are NOT included in NII when recognized for regular tax purposes. Instead, they become NII at the point of actual cash distribution from the foreign corporation. This creates timing mismatches: a US shareholder of a CFC pays regular income tax on $1,000,000 NCTI in 2026, but no NIIT until eventual distribution, at which point the §959 PTEP recovery interacts with NIIT in complicated ways.
Reg §1.1411-10(g) allows an irrevocable election to "synchronize" NII recognition with regular tax recognition - treating CFC and QEF inclusions as NII at the time of inclusion, with corresponding tax-free PTEP recovery later.
| Election Mechanic | Detail |
|---|---|
| Who can elect | US person who is a US shareholder of a CFC or US person owning stock of a PFIC for which a QEF election is in effect (the election does not apply to §1296 mark-to-market PFICs) |
| When to elect | First year the individual would be subject to NIIT if elections made. Generally first year MAGI exceeds threshold and CFC/QEF inclusions occur |
| Where to elect | Form 8960 - check the election box; attach statement identifying the CFC/QEF and election |
| Effect | CFC/QEF inclusions included in NII when recognized for regular tax; later distributions of PTEP excluded from NII |
| Revocation | Election is irrevocable; cannot be undone |
| Cost | Earlier NIIT recognition; benefit is matching the cash flow of regular tax |
The issue: whether a US-foreign country tax treaty foreign tax credit can offset NIIT. On August 31, 2026, the Federal Circuit held in Estate of Bruyea v. United States (US-Canada) and Christensen v. United States (US-France) that it cannot, reversing the Court of Federal Claims: the treaty credit provisions are subject to the Code limits, and §§26(b), 27 and 901 confine foreign tax credits to taxes imposed under Chapter 1, while NIIT under §1411 is in Chapter 2A.
| Case | Holding | Citation |
|---|---|---|
| Bruyea v. United States | Court of Federal Claims (2024) allowed treaty FTC against NIIT for a US-Canada dual citizen; reversed by the Federal Circuit on August 31, 2026, which held the US-Canada treaty provides no FTC against NIIT. | 174 Fed. Cl. 238 (2024), rev'd, No. 2025-1563 (Fed. Cir. Aug. 31, 2026) |
| Christensen v. United States | Court of Federal Claims (2023) allowed treaty FTC against NIIT under US-France treaty; reversed by the Federal Circuit on August 31, 2026 | 168 Fed. Cl. 263 (2023), rev'd, No. 2024-1284 (Fed. Cir. Aug. 31, 2026) |
| Toulouse v. Commissioner | Tax Court - rejected the argument that the US-France treaty allows FTC to offset NIIT | 157 T.C. 49 (2021) |
| IRS position | Denies treaty FTC against NIIT; position upheld by the Federal Circuit on August 31, 2026 | IRS Chief Counsel Advice Memo 202118011 |
For non-grantor trusts and decedent's estates, the §1411 threshold is the dollar amount at which the highest §1(e) bracket begins. For 2026, that threshold is $16,000 (compared to individual thresholds of $200K-$250K). Almost every trust with investment income triggers NIIT.
| Trust / Estate NIIT Element | Treatment |
|---|---|
| Threshold | $16,000 (2026, the §1(e) top bracket start) |
| NIIT base | Lesser of (a) undistributed NII or (b) AGI minus threshold |
| Distributions | Income distributed to beneficiaries via DNI carries the NII character to them; trust NIIT only on undistributed portion |
| Charitable remainder trust (CRT) | Special tier rules under Reg §1.1411-3(d); accumulated NII (ANII) tracked separately |
| Electing Small Business Trust (ESBT) | S-corp portion and non-S portion handled separately; complex Reg §1.1411-3(c) mechanics |
| Grantor trust | Income flows to grantor; NIIT computed on grantor's return (no trust-level NIIT) |
| Bankruptcy estate of individual | Treated as a married taxpayer filing a separate return for §1411 purposes (Reg §1.1411-3(b)(2)(ii)), so the $125,000 threshold applies |
| Foreign trust | Generally not subject to NIIT (no Chapter 2A application to foreign persons); separate accumulation distribution rules apply via Form 3520 |
Convert passive activities to nonpassive by genuinely increasing participation. A 600-hour annual commitment to a rental real estate activity transforms it from §1411 T/B to non-T/B for NIIT purposes - eliminating NIIT on rental income or gain on disposition. Hours must be documented contemporaneously.
A spouse with no other career commitments can become the real estate professional. Once REP status applies for that spouse, rental activities can be grouped for material participation under Reg §1.469-9(g) election - making material participation in each rental a single test rather than activity-by-activity.
Realize capital losses to offset capital gains. Capital losses fully offset capital gains within NII. Net gain attributable to dispositions cannot be less than zero, and a net capital loss reduces other NII only to the extent allowed under §1211(b) ($3,000, or $1,500 MFS) (Reg §1.1411-4(d)(2)). Excess capital loss carries forward.
Tax-exempt municipal bond interest is excluded from both MAGI and NII. Substituting taxable corporate bonds with tax-exempt municipals (where after-tax yield favors munis) reduces both MAGI exposure to threshold and direct NII. Especially powerful for Clients close to threshold who lose only marginal income to make the swap.
Donating long-term appreciated stock to a public charity avoids capital gain recognition entirely - removes that gain from NII. Donor receives FMV charitable deduction (subject to §170 percentage limits). Compared to selling and donating cash, this strategy saves both regular capital gains tax and NIIT on the unrealized appreciation.
A Roth conversion increases MAGI for the year of conversion. If the taxpayer is below the NIIT threshold or in a year with low investment income, the Roth conversion may push MAGI over threshold, triggering NIIT on existing investment income. Modeling required: sometimes converting in low-investment-income years still net-saves; sometimes deferring conversion saves more.
Qualified Charitable Distributions from IRAs (up to $111,000 for 2026 ($108,000 for 2025)) count toward Required Minimum Distribution but are NOT included in AGI. This keeps MAGI lower, reducing both NIIT exposure and Medicare IRMAA surcharges.
Traditional 401(k), traditional IRA (if deductible), HSA, SEP-IRA contributions all reduce MAGI. For an entrepreneur Client at MAGI $260,000 with $50,000 of NII, a $30,000 solo 401(k) contribution pulls MAGI to $230,000 - reducing NIIT base from $10,000 to $0 (MAGI below threshold). Tax saving: $380 NIIT plus ~$10,000 regular income tax.
Material participation is tested annually for each activity. A Client who materially participated in 2024 may not in 2026 if hours drop below the 500-hour threshold and no other test applies. Don't assume continuity.
Without the Reg §1.469-9(g) aggregation election, each rental property must independently satisfy material participation. With 10 properties and 100 hours each (1,000 total), the taxpayer fails material participation on each because no single property crosses 500 hours. The aggregation election (filed with the original return, generally) treats all rentals as one activity - producing 1,000 hours of total participation, easily clearing 500.
Wages and SE earnings are NOT NII under §1411(c)(6) because they're already subject to Medicare tax under §1401(b) or §3101(b)(2). A practitioner who lists W-2 wages on Form 8960 produces wrong NIIT. Wages affect MAGI (so help trigger threshold), but they are not NII.
The $250K single / $500K MFJ home sale exclusion under §121 carries through to NIIT - excluded portion is NOT in NII. Only the excess over the §121 exclusion counts. A Client selling a primary residence at $700K MFJ gain has $200K in NII, not $700K.
The §1.1411-10(g) election to include CFC/PFIC inclusions in NII at the time of regular tax recognition is irrevocable. Once made, cannot be undone. Failure to elect when first below threshold then crossing threshold in a later year is a common timing issue. Verify the election history when taking over a Client from another preparer.
Capital loss carryforwards offset capital gains for NIIT purposes (subject to the §1411 framework which mirrors §1211(b)). However, the carryforward amount must be tracked separately on Form 8960 - the regular-tax carryforward may differ from the NIIT carryforward if §1411 trade or business exclusions changed the character of prior-year losses.
Dual citizens of US and treaty countries who paid foreign tax and owe NIIT can no longer rely on a treaty FTC to offset NIIT. The Federal Circuit rejected the argument in Bruyea and Christensen on August 31, 2026, reversing the Court of Federal Claims, and the Tax Court rejected it in Toulouse. Review the specific treaty text before claiming the credit.
Non-grantor trusts with even modest investment income face NIIT. A trust with $50,000 of dividend and capital gain income and only $20,000 distributed to beneficiaries has $30,000 of undistributed NII. With trust AGI at $30,000 ($50,000 less the $20,000 distribution deduction allowed in computing AGI under §67(e)(2)) and threshold $16,000, the lesser of undistributed NII ($30,000) or AGI excess ($14,000) is $14,000 - producing $532 NIIT at the trust level. Distribution planning is critical.
Primary authority: IRC §1411 (imposition of tax), §1411(a)(1) (tax imposed on individuals), §1411(a)(2) (tax imposed on estates and trusts), §1411(b) (threshold amount - $200K single, $250K MFJ, $125K MFS, NOT indexed), §1411(c)(1) (definition of net investment income), §1411(c)(1)(A)(i) (investment-type gross income), §1411(c)(1)(A)(ii) (income from §1411 trade or business), §1411(c)(1)(A)(iii) (net gain from disposition of property), §1411(c)(1)(B) (allowable deductions allocable to NII), §1411(c)(2) (§1411 trade or business - passive activity or trading), §1411(c)(5) (retirement plan distribution exclusion), §1411(c)(6) (SE income exclusion - already subject to §1401(b) Medicare), §1411(d) (MAGI definition - FEIE addback), §1411(e) (special rule for NRA). §469 (passive activity loss), §469(c)(7) (real estate professional - 50% and 750 hour two-prong test), §469(c)(7)(C) (real property trade or business categories). §121 (home sale exclusion - applies to NII as well). §1(e) (estate/trust top bracket - $16,000 for 2026). §1401(b) (Medicare SE tax). §3101(b)(2) (Additional Medicare Tax). §27 / §901 (foreign tax credit - chapter 1 only, per the IRS and the Federal Circuit in Bruyea and Christensen). §165(g) / §166 (worthless security / bad debt - special §6511 SOL). Treasury Regulations §1.1411-1 through §1.1411-10. Reg §1.1411-3(c) (ESBT). Reg §1.1411-3(d) (CRT accumulated NII). Reg §1.1411-4 (net investment income computation). Reg §1.1411-5 (§1411 trade or business). §1411(c)(4) and proposed Reg §1.1411-7 (gain from disposition of partnership or S-corp interest; final §1.1411-7 is reserved). Reg §1.1411-9 (SE income exception). Reg §1.1411-10(g) (CFC/QEF inclusion election). Reg §1.469-5T(a) (seven material participation tests). Reg §1.469-9(g) (rental aggregation election). Form 8960 and Instructions. Bruyea v. United States, 174 Fed. Cl. 238 (2024), rev'd, No. 2025-1563 (Fed. Cir. Aug. 31, 2026). Christensen v. United States, 168 Fed. Cl. 263 (2023), rev'd, No. 2024-1284 (Fed. Cir. Aug. 31, 2026). Toulouse v. Commissioner, 157 T.C. 49 (2021). Hakkak v. Commissioner, T.C. Memo 2020-46 (material participation documentation).