The tax on unit trusts falls on you, not the trust. A unit investment trust is a pass-through for federal tax purposes, so every dollar of dividends, interest, and capital gain it earns is taxed on your personal return in the year the trust earns it, whether you took the money in cash or reinvested it.1eCFR. 26 CFR 1.851-7 – Certain Unit Investment Trusts What you actually owe depends on the kind of income the trust throws off, how long you have held your units, and where you sit in the federal brackets.
Why You Pay Tax Even When the Trust Doesn’t Distribute Cash
A UIT pools investor money into a fixed portfolio of stocks, bonds, or other securities. The trust itself owes no federal income tax. Instead, each holder is treated as owning a proportionate share of the underlying assets, and every item of income, gain, loss, or deduction is taxed directly to the holder as if received on the date the trust received it.1eCFR. 26 CFR 1.851-7 – Certain Unit Investment Trusts
The practical consequence is that leaving earnings inside the trust does not defer tax. Your fund company reports your share of income on Form 1099-DIV every year, and you owe tax on that amount whether you pocketed it or let it compound.2Internal Revenue Service. Form 1099-DIV, Dividends and Distributions
Tax on Dividends
Stock dividends passed through the trust land in one of two categories on your 1099-DIV, and the category controls the rate.
Qualified Dividends
Qualified dividends are taxed at the long-term capital gains rates of 0%, 15%, or 20%, keyed to taxable income.3Office of the Law Revision Counsel. 26 USC 1 – Tax Imposed For 2026, single filers with taxable income up to $49,450 (or $98,900 for joint filers) pay 0%. The 15% rate runs up to $545,500 for singles and $613,700 for joint filers. Above those thresholds, the rate is 20%.
To get the qualified rate, you must hold the units more than 60 days during the 121-day period beginning 60 days before the ex-dividend date. Buy-and-hold investors clear this without effort; buying just before a distribution and selling just after does not.
Ordinary Dividends
Dividends that fail the holding-period test, along with distributions from REITs and money market funds, are taxed as ordinary income. Ordinary rates for 2026 run from 10% to 37%, with the top rate applying above $640,600 for singles and $768,700 for joint filers.p>
Tax on Interest Income
Trusts holding bonds, Treasuries, or other debt produce interest rather than dividends. Interest passes through to you and is taxed at your ordinary income rate, the same as interest from a bank account. The fund company reports it on Form 1099-DIV or Form 1099-INT.
One exception matters if you live in a high-tax state: interest from U.S. Treasury securities held inside the trust is exempt from state and local income tax, though it remains fully federally taxable. The exempt portion is typically broken out on your year-end statement.
Capital Gains When You Sell Your Units
Selling, exchanging, or gifting units triggers a gain or loss. Subtract your cost basis (what you paid, including commissions and fees) from your sale proceeds.
Short-Term vs. Long-Term
Gains on units held more than one year are long-term and taxed at the 0%, 15%, or 20% rates above.4Office of the Law Revision Counsel. 26 USC 1222 – Other Terms Relating to Capital Gains and Losses Gains on units held one year or less are short-term and taxed at ordinary rates, which for high earners can be roughly double the long-term rate.5Internal Revenue Service. Topic No. 409, Capital Gains and Losses
Losses offset gains for the year. If your losses exceed your gains, you can deduct up to $3,000 of the excess against ordinary income ($1,500 if married filing separately) and carry the rest forward.
Cost Basis Methods
Because basis drives the size of the gain, the method you use matters. The IRS allows three approaches for fund shares:
- Average cost divides the total cost of all shares you own by the number of shares. This is the default for most UIT and mutual fund accounts and the simplest option when you have bought in at different prices.
- First in, first out assumes the oldest shares are sold first. It is the IRS default for individual securities and can produce larger gains if your earliest purchases were at the lowest prices.
- Specific identification lets you choose exactly which shares to sell, which gives you the most control over the tax bill. You must identify the specific shares to your broker before the sale settles.
Whichever method you use, stay consistent. If you have been using average cost, you generally cannot switch to specific identification for shares you have already sold.
Capital Gain Distributions From the Trust
The trust itself can sell securities inside the portfolio at a profit. When that happens, the gain is distributed to holders and reported in Box 2a of Form 1099-DIV.2Internal Revenue Service. Form 1099-DIV, Dividends and Distributions You owe tax on these distributions whether they were paid in cash or automatically reinvested.
The IRS treats capital gain distributions as long-term regardless of how long you have personally held the units.6Internal Revenue Service. Mutual Funds (Costs, Distributions, etc.) 4 If the distribution is reinvested, add the reinvested amount to your cost basis. Skip that step and you will pay tax on the same money twice when you eventually sell.
The 3.8% Net Investment Income Tax
Higher-income investors owe an extra 3.8% on top of the regular rates. The net investment income tax applies to the lesser of your net investment income or the amount by which your modified adjusted gross income exceeds $200,000 (single) or $250,000 (married filing jointly).7Office of the Law Revision Counsel. 26 USC 1411 – Imposition of Tax These thresholds are not adjusted for inflation.
Net investment income includes dividends, interest, capital gains, and capital gain distributions from unit trusts.8Internal Revenue Service. Topic No. 559, Net Investment Income Tax A single filer with $230,000 in modified AGI, $50,000 of which comes from trust distributions, pays the 3.8% surtax on $30,000 (the amount above $200,000), adding $1,140. You calculate this on Form 8960.
Wash Sales
Sell units at a loss and buy the same or substantially identical investment within 30 days before or after, and the IRS disallows the loss under the wash sale rule.9Office of the Law Revision Counsel. 26 USC 1091 – Loss from Wash Sales of Stock or Securities The disallowed loss is added to the basis of the replacement units, deferring the deduction until you sell those. If the replacement purchase happens inside an IRA or Roth IRA, the loss is permanently forfeited, because the IRA’s basis does not increase.
The “substantially identical” standard is where UIT investors get tripped up. The IRS has not published a bright-line definition. Two funds from different companies tracking different indexes with different expense ratios are generally distinct enough to avoid the rule. Selling one S&P 500 index trust and immediately buying another S&P 500 index trust from a different provider is riskier, because the closer the portfolios, the more likely the IRS treats them as substantially identical. Automatic dividend reinvestment can also trigger a wash sale if a reinvestment falls inside the 30-day window after a loss sale, so turn off auto-reinvest before harvesting a loss.
Units Held in IRAs and 401(k)s
Everything above applies to units held in a taxable brokerage account. Inside a traditional IRA or 401(k), dividends, interest, and gains accumulate tax-deferred, and you owe nothing until you take distributions, which are then taxed as ordinary income regardless of their original character. In a Roth IRA, qualified distributions are tax-free. The trade-off is that you give up the preferential qualified dividend and long-term capital gains rates and cannot harvest losses to offset gains elsewhere.
Forms You Will File
Which forms you touch depends on what the trust generated and whether you sold anything.
- Form 1099-DIV arrives from the fund company by mid-February, reporting ordinary dividends (Box 1a), qualified dividends (Box 1b), and capital gain distributions (Box 2a).2Internal Revenue Service. Form 1099-DIV, Dividends and Distributions
- Schedule B is required if total ordinary dividends or taxable interest exceeds $1,500.10Internal Revenue Service. 2025 Instructions for Schedule B (Form 1040)
- Form 8949 and Schedule D report unit sales. List each transaction on 8949 to reconcile with Form 1099-B, then carry the totals to Schedule D.11Internal Revenue Service. About Form 8949, Sales and Other Dispositions of Capital Assets
- Form 8960 calculates the 3.8% net investment income tax if you owe it.
Capital gain distributions you did not trigger by selling can often go directly on line 7a of Form 1040 without Schedule D, provided you have no other transactions requiring that form.6Internal Revenue Service. Mutual Funds (Costs, Distributions, etc.) 4 Check the Form 1040 instructions for the specific conditions.
Deadlines and Estimated Payments
The federal return for the 2025 tax year is due April 15, 2026.12Internal Revenue Service. When to File An automatic six-month extension covers filing but not payment; anything owed still has to be paid by April 15 or interest starts running.
If your trust income will leave you owing at least $1,000 after withholding and credits, the IRS expects quarterly estimated payments rather than a single April settlement.13Internal Revenue Service. Estimated Tax To avoid an underpayment penalty, total withholding and estimated payments must cover at least 90% of the current-year liability, or 100% of last year’s tax (110% if AGI exceeded $150,000). The prior-year safe harbor is the easier target, since you know the number before the year starts.