DST Income and the 3.8% Net Investment Income Tax (NIIT)

DST rent is net investment income because it is rent from a passive activity

Section 1411(c)(1) defines net investment income to include gross income from rents, other than rents derived in the ordinary course of a trade or business that is not a passive activity, plus net gain from disposing of property to the extent taken into account in computing taxable income, less properly allocable deductions. A DST interest is a share of a rental property you are treated as owning directly under Rev. Rul. 2004-86, and the trustee, not you, conducts its limited activities.

Section 469(c)(2) treats rental activities as passive regardless of participation, as covered at DST passive losses and sale. So the ordinary-course exception does not help, and your share of the trust's rent goes into net investment income. The DST itself is a grantor trust, which the Form 8960 instructions list among trusts not subject to the tax at the trust level; the income lands on your return.

The tax applies only above fixed thresholds, and only to the smaller of two numbers

For individuals the tax is 3.8% of the lesser of net investment income or modified adjusted gross income above the threshold. Under section 1411(b) and the IRS questions and answers on the tax, the threshold is $250,000 for married filing jointly and qualifying surviving spouses, $125,000 for married filing separately and $200,000 for single and head of household filers. The IRS notes these amounts are not indexed for inflation.

Two consequences follow. A retiree with modest other income may hold DSTs and never owe the tax. A seller with a large gain in the year of a taxable sale may owe it on everything, because the gain itself pushes MAGI far over the line.

Interest, expenses and depreciation reduce DST net investment income dollar for dollar

Under Reg. section 1.1411-4(f)(2)(i), deductions described in section 62(a)(4) that are allocable to rents are taken into account in determining net investment income. Those are the deductions that produce your net rental figure on Schedule E: the trust's mortgage interest, operating expenses and fees passed through to you, and your depreciation.

That is why the same depreciation that shelters part of your cash distribution, as explained at return of capital vs income in DST distributions, also lowers this tax. Depreciation reduces your basis, so more gain, and more net investment income, appears in a later taxable sale.

Hypothetical, rounded, joint filers: MAGI of $320,000, including $30,000 of net DST rental income after depreciation and $20,000 of other investment income. Net investment income is $50,000; MAGI exceeds the threshold by $70,000; the tax is 3.8% of $50,000, or $1,900. If depreciation were $15,000 lower, net rental income and MAGI would each rise by $15,000 and the tax by $570. Run your own numbers with your CPA.

A 1031 exchange keeps deferred gain out of the tax; a cash-out year brings it in

Section 1411(c)(1)(A)(iii) counts net gain only to the extent taken into account in computing taxable income. Gain deferred under section 1031 is not, so exchanging into a DST, or from one DST into the next, adds no net investment income on the deferred portion. Boot you recognize is counted. The mechanics for a rental seller are at does a 1031 defer the NIIT.

When a trust sells and you take your share in cash, the recognized gain, including unrecaptured section 1250 gain from depreciation, is net investment income, and the gain also raises MAGI. Rental losses released under section 469(g) on a fully taxable disposition of your entire interest are taken into account under Reg. section 1.1411-4(g)(9). The cash-out arithmetic is at when the sponsor sells early.

The real estate professional exception does not reach DST income in practice

Reg. section 1.1411-4(g)(7) gives a safe harbor to a real estate professional under section 469(c)(7)(B) who participates in a rental real estate activity for more than 500 hours in the year, or in five of the prior ten years: the rent is then treated as derived in the ordinary course of a trade or business and escapes the tax. A DST owner does not participate in the trust's operations, which the ruling assigns to the trustee, so the hours cannot be logged for the DST. The tests are at real estate professional status.

For investors whose income will stay above the thresholds for years, the practical levers are timing and deferral: keep gain inside exchanges, spread taxable events across years where you can, and coordinate with the 2026 tax numbers for real estate sellers. Distributions are not assured, and the tax follows the income the trust actually earns.