Trust Income Tax Estimator

Distributable Net Income (DNI) is arguably the most important concept in trust taxation. It serves as both the ceiling on the trust's distribution deduction and the ceiling on the amount taxable to beneficiaries. Think of DNI as the "tax character passport" — it determines how much income can be shifted from the trust to its beneficiaries, and what kind of income it is.

How DNI is calculated:

• Start with trust taxable income — all gross income less allowable deductions
• Add back the distribution deduction — DNI is computed without the distribution deduction itself
• Add back the personal exemption ($300 for simple trusts, $100 for complex trusts)
• Remove capital gains allocated to corpus (unless the trust instrument or state law allocates them to income)
• Add tax-exempt income (net of allocable expenses)

Why DNI matters: If a trust has $100,000 of DNI and distributes $80,000 to beneficiaries, the trust deducts $80,000 and pays tax on only $20,000. The beneficiaries report $80,000 on their individual returns, taxed at their own (usually lower) marginal rates. But if the trust distributes $120,000, only $100,000 is deductible — the excess $20,000 is treated as a tax-free distribution of trust corpus.

DNI also carries the character of the trust's income. If the trust earns $60,000 in ordinary income and $40,000 in qualified dividends, a $50,000 distribution would carry 60% ordinary and 40% qualified dividend character to the beneficiary (proportional allocation). This character preservation can be significant when the income includes tax-favored types like qualified dividends or tax-exempt interest.

The IRS classifies trusts into two categories for income tax purposes — simple trusts and complex trusts — and the distinction significantly affects how income is taxed and when distributions are deductible.

Simple trusts must meet all three criteria:

• Required to distribute all income currently: The trust instrument requires that all fiduciary accounting income (FAI) is distributed to beneficiaries each year. No accumulation is allowed.
• No charitable contributions: The trust does not make any payments to charity from trust income.
• No corpus distributions: The trust does not distribute any principal (corpus) during the tax year.

Complex trusts are everything else — any trust that does not meet all three simple trust requirements. This includes trusts that:

• Have discretion to accumulate income rather than distribute it
• Make charitable contributions from income
• Distribute principal to beneficiaries

The tax treatment differs in several key ways. Simple trusts get a $300 personal exemption while complex trusts get only $100. Simple trusts automatically get a distribution deduction for all income (capped at DNI), while complex trusts only deduct amounts actually distributed or required to be distributed. Complex trusts can also make discretionary distributions of corpus, which do not carry taxable income character (up to the extent they exceed DNI).

A trust can switch between simple and complex classification from year to year. For example, if a trust normally distributes all income (simple) but in one year also distributes principal, it is complex for that year.

The 3.8% Net Investment Income Tax (also called the Medicare surtax) applies to trusts and estates at a much lower income threshold than it does for individuals. For 2025, trusts trigger NIIT on the lesser of undistributed net investment income or the amount by which adjusted gross income exceeds approximately $15,200 (the threshold at which trusts hit the top 37% bracket).

Compared to individual thresholds:

• Single filers: NIIT applies above $200,000 MAGI
• Married filing jointly: NIIT applies above $250,000 MAGI
• Trusts and estates: NIIT applies above approximately $15,200 — more than 13 times lower than the individual threshold

This means a trust with $50,000 of investment income would owe approximately $1,330 in NIIT alone (3.8% on the $34,800 above the threshold), on top of the regular income tax. The combined marginal rate at the trust level can reach 40.8% (37% ordinary rate plus 3.8% NIIT).

Key planning opportunity: NIIT applies only to undistributed net investment income. If the trust distributes the investment income to beneficiaries, the NIIT shifts to the beneficiary level, where the much higher $200,000/$250,000 thresholds apply. For many beneficiaries, this means the NIIT is completely avoided. This makes distribution planning doubly valuable — it saves on both the regular income tax rate compression and NIIT exposure.

Capital gains are one of the most nuanced areas of trust taxation. By default, capital gains are allocated to trust corpus (principal) rather than trust income, which means they are typically not included in DNI and are therefore not deductible when the trust makes distributions.

Default treatment:

• Capital gains stay in the trust: They are taxed at the trust's compressed capital gains brackets — 0% up to $3,150, 15% from $3,150 to $15,450, and 20% above $15,450 (2025 rates).
• NIIT adds 3.8%: Capital gains above the ~$15,200 threshold also incur the 3.8% NIIT, bringing the maximum trust capital gains rate to 23.8%.
• Distribution does not shift gains: Even if the trustee distributes cash, the capital gain character stays at the trust level unless specific conditions are met.

Exceptions — when capital gains can be distributed:

• Trust instrument allocates gains to income: If the trust document specifically provides that capital gains are treated as part of distributable income
• State law allocation: Some states allow the Uniform Principal and Income Act to allocate gains to income
• Consistent trustee practice: If the trustee has a consistent practice of distributing capital gains as part of distributions
• Final year of the trust: In the trust's final tax year, all gains pass through to the beneficiaries

This is an area where trust drafting and state law significantly affect the tax outcome. If capital gains can be distributed, the beneficiary would pay at their own capital gains rate (often 0% or 15% for lower-income beneficiaries), which can save meaningful tax compared to the trust's 20% plus 3.8% NIIT rate.

Because trusts hit the top tax bracket so quickly, distribution planning is the single most effective tool for reducing the overall tax burden on trust income. Here are the primary strategies trustees and advisors use.

Key distribution planning strategies:

• Distribute all income annually: The simplest approach is to distribute all trust income to beneficiaries in lower tax brackets. This shifts the income out of the compressed trust brackets entirely.
• 65-day election (Section 663(b)): Complex trusts can elect to treat distributions made in the first 65 days of the following year as if they were made on December 31 of the prior year. This gives the trustee time to see the full-year income picture before deciding how much to distribute.
• Timing distributions to match income: Coordinate distributions with the trust's income events. If the trust will realize a large capital gain, consider whether the trust instrument allows distributing that gain.
• Distribute to the lowest-bracket beneficiaries: If the trust has multiple beneficiaries, prioritize distributions to those in the lowest marginal brackets. A distribution to a beneficiary in the 10% bracket saves far more than one to a beneficiary already in the 37% bracket.
• Consider state taxes: Some states have their own trust income taxes. A distribution may also save state taxes if the beneficiary resides in a lower-tax state than the trust's situs.

Important caveats: Tax savings should never be the sole driver of distribution decisions. The trustee has a fiduciary duty to follow the trust instrument and consider all beneficiaries' interests. If the trust is designed to accumulate income for future beneficiaries, distributing everything now for a tax benefit may violate the grantor's intent and the trustee's fiduciary obligations.

The 65-day rule, codified in IRC Section 663(b), is a valuable planning tool that allows complex trusts (and estates) to treat distributions made in the first 65 days of a new tax year as if they were made on the last day of the prior tax year.

How it works:

• Election on Form 1041: The trustee must make the election on the trust's income tax return (Form 1041) for the year in which the distribution is being "pulled back."
• Deadline: Distributions must be made by March 6 of the following year (65 days after January 1).
• Only for complex trusts: Simple trusts do not need this election because they are required to distribute all income currently. The 663(b) election benefits complex trusts that have discretionary distribution powers.
• Capped at DNI: The amount treated as a prior-year distribution cannot exceed the trust's DNI for that prior year, and combined with actual prior-year distributions, the total deduction cannot exceed DNI.

Why this is so useful: Without the 65-day rule, trustees would need to estimate the trust's full-year income before December 31 and make distribution decisions under uncertainty. The 65-day rule gives them until early March — often enough time to receive all final K-1s and brokerage statements — before deciding how much to distribute.

For example, a trust with $100,000 of 2025 income could wait until February 2026 to see the final numbers, distribute $80,000 to beneficiaries by March 6, 2026, elect 663(b) on the 2025 Form 1041, and deduct $80,000 against 2025 trust income. The trust pays tax on only $20,000 at its compressed rates instead of the full $100,000.

The distinction between grantor trusts and non-grantor trusts is fundamental to trust income taxation because it determines who pays the tax — the trust or the individual who created it.

Grantor trusts:

• Tax is paid by the grantor: All trust income, deductions, and credits are reported on the grantor's individual tax return (Form 1040), not the trust's return. The trust is essentially "invisible" for income tax purposes.
• No compressed brackets: Because the income flows to the grantor's individual return, it benefits from the much wider individual tax brackets.
• Common types: Revocable living trusts, intentionally defective grantor trusts (IDGTs), and trusts where the grantor retains certain powers (under IRC Sections 671-679).
• Estate planning advantage: The grantor paying the income tax is like a tax-free gift to the trust beneficiaries — the trust assets grow without being diminished by tax payments.

Non-grantor trusts:

• Trust pays its own tax: The trust files its own Form 1041 and pays tax at the compressed trust brackets on any undistributed income.
• Distribution deduction available: Income distributed to beneficiaries reduces the trust's taxable income (up to DNI), and beneficiaries report it on their returns.
• Common types: Irrevocable trusts where the grantor has relinquished sufficient control, charitable remainder trusts (partially), and testamentary trusts.

This calculator focuses on non-grantor trust taxation, where the distribution deduction and compressed brackets create the planning opportunity. If you have a grantor trust, the compressed trust brackets do not apply — all income flows through to the grantor's individual return.

Yes, most states impose their own income tax on trusts, and the rules for determining which state can tax a trust vary significantly. This is an area of active litigation and legislative change, making it one of the most complex aspects of trust tax planning.

Common state triggers for taxing trust income:

• Grantor's state of residence: Many states tax trusts created by a resident grantor, regardless of where the trust or beneficiaries are currently located.
• Trustee's location: Some states tax trusts administered within their borders by a resident trustee.
• Beneficiary's residence: A few states tax trust income based on where the beneficiaries live.
• Trust situs or administration: The state where the trust is legally domiciled or administered may assert taxing jurisdiction.
• Source income: Income from real property or business activities in a state is generally taxable regardless of trust domicile.

States with no income tax on trusts: Alaska, Florida, Nevada, New Hampshire (dividends and interest only), South Dakota, Tennessee, Texas, Washington, and Wyoming. This is why many trust planners consider domiciling trusts in these states, though the analysis depends on the specific nexus rules of the grantor's and beneficiaries' home states.

The interaction between federal and state trust taxation makes distribution planning even more impactful. A trust domiciled in a high-tax state like California (top rate 13.3%) that distributes to a beneficiary in Florida could save not only the federal rate differential but also the entire state tax on the distributed income.

The Kiddie Tax (IRC Section 1(g)) is an important limitation on the tax savings achievable by distributing trust income to minor beneficiaries. It was designed precisely to prevent parents and grandparents from shifting investment income to children in lower brackets.

How the Kiddie Tax works (2025 rules):

• Applies to children under 19 (or under 24 if a full-time student) who have unearned income exceeding approximately $2,500 (2025 threshold).
• First $1,250 of unearned income: Tax-free (standard deduction for dependents).
• Next $1,250: Taxed at the child's own rate (typically 10%).
• Above $2,500: Taxed at the parent's marginal tax rate. This eliminates the benefit of the child's lower bracket.

Impact on trust distribution strategy: If you are distributing trust income to a child subject to the Kiddie Tax, the tax savings may be minimal or nonexistent. Income above the threshold is taxed at the parent's rate, which might be the same or even higher than the trust's rate. The distribution would still avoid the trust's compressed brackets, but would effectively be taxed at the parent's rate instead.

Planning considerations: For distributions to minor beneficiaries, consider keeping amounts below the Kiddie Tax threshold, or focus distributions on adult beneficiaries (such as adult children or others) who are in genuinely lower tax brackets. The Kiddie Tax does not apply to earned income, so it specifically targets the type of investment income that trusts typically generate.

After the child turns 19 (or 24 if a student), the Kiddie Tax no longer applies, and distributions can produce full bracket arbitrage if the beneficiary is in a lower bracket than the trust.