IRS Tax Rules for Trust Funds: Rates, Form 1041, and Penalties

Trust fund IRS tax rules turn on one question: who the IRS treats as the owner of the trust’s assets. If the person who set up the trust kept meaningful control, the IRS ignores the trust and taxes the income on that person’s own Form 1040. If the grantor gave up control, the trust becomes its own taxpayer and pays tax on a brutally compressed schedule that reaches the top 37% federal rate at just $16,000 of taxable income in 2026.¹ Everything else — who files what, who owes what, what the trustee is personally on the hook for — flows from that first question.

Who Pays the Tax: Grantor or Trust

Every trust is either a grantor trust or a non-grantor trust for federal tax purposes.

A grantor trust is one where the grantor kept at least one significant power over the assets or income. The clearest example is a revocable living trust, which the grantor can amend or unwind at any time.² Other triggers include a reversionary interest worth more than 5% of the trust’s value,³ the ability to direct income to the grantor or their spouse,⁴ or certain administrative powers like borrowing from the trust without adequate security.⁵ When any of these apply, all of the trust’s income, deductions, and credits land on the grantor’s personal Form 1040, taxed at individual rates under the grantor’s Social Security number.⁶ A separate trust return is usually optional.

A non-grantor trust exists when the grantor gave up all of those powers, which almost always means the trust is irrevocable. The trust becomes a separate taxable entity. It needs its own Employer Identification Number, files its own Form 1041, and pays tax on any income it keeps.

The Compressed Trust Rate Schedule

The reason grantor status matters so much is that non-grantor trusts pay tax on an extremely narrow bracket schedule. For 2026:⁷

10% on taxable income up to $3,300
24% from $3,301 to $11,700
35% from $11,701 to $16,000
37% over $16,000

A single individual filer does not reach the 37% bracket until taxable income exceeds $640,600 in 2026.⁸ A trust gets there at roughly 2.5% of that income. Layer on the 3.8% Net Investment Income Tax, which kicks in at the same $16,000 threshold for trusts,⁹ and a trust retaining investment income above that line faces a combined marginal federal rate of 40.8%.

Personal exemptions for non-grantor trusts are small: $300 for a simple trust (one required to distribute all current income), $100 for a complex trust, and $5,300 for a qualified disability trust in 2026.

The practical takeaway: retaining income inside a non-grantor trust is expensive. The rules that follow exist mainly to let trustees push income out to beneficiaries, where it usually faces much lower rates.

How Distributions Shift Income to Beneficiaries

The IRS treats trust income as a conduit. Income the trust distributes is taxed to the beneficiary; income the trust keeps is taxed to the trust. The mechanism is Distributable Net Income (DNI).

Distributable Net Income

DNI is the ceiling on both sides of the equation: the most the trust can deduct for distributions, and the most beneficiaries have to include in their own income. The trust calculates it by starting with taxable income, adding back the distribution deduction and personal exemption, generally excluding capital gains allocated to principal, and adding back tax-exempt interest.¹⁰ Anything distributed beyond DNI is treated as a nontaxable return of principal.

Schedule K-1 to Beneficiaries

Beneficiaries report their share of DNI on their personal Form 1040 based on the Schedule K-1 the trustee sends them.⁶ Income keeps its character: qualified dividends stay qualified dividends, tax-exempt interest stays tax-exempt, and each category is reported separately rather than lumped into ordinary income.¹¹

The 65-Day Election

Trustees rarely know a trust’s exact income before year-end. Federal regulations let the trustee treat any distribution made within the first 65 days of a new tax year as if it had been made on the last day of the prior year.¹² The election is made on Form 1041 for the prior year and is irrevocable once made. The amount cannot exceed the prior year’s income or DNI, reduced by distributions actually made in that year. It is one of the few tools that lets a trustee look at final numbers and then decide whether to shift income out of the trust’s compressed brackets.

Capital Gains Get Trapped in the Trust

Capital gains are the trap. Under the default rule, gains allocated to the trust’s principal are excluded from DNI and taxed at the trust level, even when the trust distributes cash to beneficiaries the same year.¹⁰ Long-term gains above the $16,000 top-bracket threshold face the 20% capital gains rate plus 3.8% NIIT, a combined 23.8% federal rate.⁹ A beneficiary in a lower bracket might have paid 15% or 0% on the same gain.

Gains can be included in DNI and passed through only if the trust instrument or state law allocates them to income, or the trustee has discretion to treat them as distributable and actually distributes them. That flexibility has to be built into the trust document; retrofitting an existing trust is rarely simple.

What Changes When the Grantor Dies

When the grantor of a revocable trust dies, the tax identity flips. The trust can no longer use the grantor’s Social Security number, because the grantor is no longer a taxpayer. The successor trustee has to apply for an EIN and start filing Form 1041 as a separate taxable entity.⁶ The compressed bracket schedule applies immediately. Income earned by trust assets after the date of death goes on the trust’s return, not the decedent’s final personal return. Banks and brokerages will need the new EIN before they will process transactions under the trust, so the application should not wait.

What the Trustee of a Non-Grantor Trust Files

The trustee carries the compliance load, and missed steps can produce penalties assessed against the trustee personally.

EIN

Every non-grantor trust needs its own EIN, available from the IRS online, by fax, or by mail. The EIN goes on every form the trust files.

Form 1041

Form 1041 reports the trust’s gross income, deductions, DNI, distribution deduction, and tax on any retained income. It is due April 15 for calendar-year trusts, or the 15th day of the fourth month after the close of a fiscal year.⁶ Form 7004 buys an automatic 5½-month extension.¹³ Filing is mandatory if the trust has any taxable income, gross income of $600 or more, or a nonresident alien beneficiary. Even a trust that distributes everything and owes nothing still files, so the IRS can match its reported distributions to what beneficiaries report.

Schedule K-1

The trustee prepares and sends a K-1 to every beneficiary who received a distribution. It breaks down each income category — ordinary, qualified dividends, tax-exempt interest, distributed capital gains, and any deductions or credits.¹⁴ K-1s are due by the same deadline as Form 1041, including any extension.

Quarterly Estimated Taxes

A non-grantor trust that expects to owe $1,000 or more after withholding and credits must pay quarterly estimates on April 15, June 15, September 15, and January 15.⁷ In the trust’s final year, the trustee can use Form 1041-T to allocate estimated payments to the beneficiaries, giving them credit for tax the trust already paid.¹⁵

Penalties for Late or Wrong Filings

Filing Form 1041 late costs 5% of the unpaid tax per month or partial month, capped at 25%. If the return is more than 60 days late, the minimum penalty is $525 (for returns due in 2026) or 100% of the unpaid tax, whichever is less. A separate 0.5%-per-month penalty applies to any unpaid balance, also capped at 25%.¹⁶

Missing or wrong K-1s trigger information return penalties. For 2026, the amounts are $60 per K-1 if corrected within 30 days, $130 if corrected by August 1, and $340 after that.¹⁷ Intentional disregard pushes each statement to $680 with no annual cap.

The IRS also uses automated matching to compare K-1 amounts against what beneficiaries actually report. Mismatches are among the most common audit triggers for trusts, along with unusually large deductions for trustee fees or administrative expenses.

Foreign Trusts: A Much Harsher Regime

Foreign trusts sit under a separate reporting system with far steeper consequences. U.S. persons who create, transfer assets to, or receive distributions from a foreign trust file Form 3520.¹⁸ A foreign trust with a U.S. owner files Form 3520-A each year, and if the trust does not file it, the U.S. owner has to attach a substitute Form 3520-A to their own Form 3520 to avoid absorbing the trust’s penalty.¹⁹

Penalties for missing these filings start at $10,000 per violation or 35% of the gross reportable amount, whichever is greater.²⁰ The IRS assesses them automatically and has shown little appetite for reasonable-cause abatement in this area.

The Trust Fund Recovery Penalty Is Not About These Trusts

People searching for trust tax rules often stumble across the Trust Fund Recovery Penalty and assume it applies. It does not. That penalty, under IRC Section 6672, targets employers who withhold payroll taxes from employees’ paychecks and then fail to remit them to the IRS.²¹ The “trust fund” is the withheld payroll tax being held in trust for the government. It has nothing to do with family trusts or estate planning trusts.

State Taxes Are a Separate Layer

Federal rules are only half the picture. Most states with an income tax also tax trust income, but each state defines a “resident” trust differently. Some look at where the trust was created, some at where the trustee lives, some at where the beneficiaries live. A trust created in one state, administered by a trustee in another, with beneficiaries elsewhere, can end up filing returns in several states at once. Choice of trustee and choice of situs are worth thinking through before the trust is funded, not after the first state return arrives.

1
Internal Revenue Service. Rev. Proc. 2025-32
2
Office of the Law Revision Counsel. 26 USC 676 – Power to Revoke
3
Office of the Law Revision Counsel. 26 USC 673 – Reversionary Interests
4
Office of the Law Revision Counsel. 26 USC 677 – Income for Benefit of Grantor
5
Office of the Law Revision Counsel. 26 USC 675 – Administrative Powers
6
Internal Revenue Service. About Form 1041
7
Internal Revenue Service. 2026 Form 1041-ES – Estimated Income Tax for Estates and Trusts
8
Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
9
Internal Revenue Service. Topic No. 559 – Net Investment Income Tax
10
Office of the Law Revision Counsel. 26 USC 643 – Definitions Applicable to Subparts A, B, C, and D
11
Office of the Law Revision Counsel. 26 USC 662 – Inclusion of Amounts in Gross Income of Beneficiaries of Estates and Trusts
12
eCFR. 26 CFR 1.663(b)-1 – Distributions in First 65 Days of Taxable Year
13
Internal Revenue Service. Instructions for Form 7004
14
Internal Revenue Service. Instructions for Schedule K-1 (Form 1041) for a Beneficiary Filing Form 1040 or 1040-SR
15
Internal Revenue Service. About Form 1041-T – Allocation of Estimated Tax Payments to Beneficiaries
16
Internal Revenue Service. Failure to File Penalty
17
Internal Revenue Service. 20.1.7 Information Return Penalties
18
Internal Revenue Service. Instructions for Form 3520
19
Internal Revenue Service. Instructions for Form 3520-A
20
Office of the Law Revision Counsel. 26 USC 6677 – Failure to File Information With Respect to Certain Foreign Trusts
21
Office of the Law Revision Counsel. 26 USC 6672 – Failure to Collect and Pay Over Tax, or Attempt to Evade or Defeat Tax