Trust Distribution Modeling Calculator

For successor trustees deciding how much trust income to distribute each year. Distributing to beneficiaries rather than retaining income in the trust can save significant federal tax — because trusts hit the 37% bracket at just $16,000 of income in 2026, while most individual beneficiaries don't reach 37% until income exceeds $640,600. This calculator shows you the numbers.

How to read the results

The calculator compares the total federal income tax paid when the trust retains income versus when it distributes income to beneficiaries. The logic follows IRC § 651 and § 661: distributions deduct from the trust's taxable income and carry the income out to beneficiaries, who report it on their personal returns via Schedule K-1.

The savings number answers: how much less total federal income tax would be paid on this trust's ordinary income if you distributed at this percentage versus retaining everything?

Key caveats:

• Beneficiary rate matters. If a beneficiary is in the 37% bracket, distributing saves nothing on income above the trust's 37% threshold. The calculator shows a negative savings figure in that case — meaning distribution actually costs more.
• This models one beneficiary's rate. If you have multiple beneficiaries in different brackets, model each separately and average the results.
• The trust exemption is small. At $100 or $300, the exemption rarely changes the analysis meaningfully. The dominant driver is the rate differential.
• State taxes are not included. Many states have their own compressed trust brackets that compound the federal advantage of distributing. Add your state's marginal rate to the beneficiary's total if state taxes are relevant.

The 65-day election: a planning tool for under-distribution

If you reach the end of December and realize the trust retained too much income, you haven't necessarily missed the window. IRC § 663(b) — the "65-day election" — lets a trustee elect to treat distributions made within the first 65 days of the following tax year as if they were made on December 31 of the prior year.¹

Practical requirements for the 65-day election:

• The trust must be a complex trust or estate — simple trusts are not eligible.
• The election is made on Form 1041, box 6 (the "65-day rule election" checkbox). It must be made by the Form 1041 due date (April 15, or September 15 with extension).
• The election covers all distributions in the 65-day window — you cannot cherry-pick which ones count for the prior year.
• The amount eligible for the election is limited to the greater of DNI or accounting income for the prior year.
• Distributions elected must actually have been made to beneficiaries — the trustee cannot retroactively construct a distribution that didn't happen.

Capital gains: a separate calculation

The distribution calculator above models ordinary trust income only — interest, dividends, rents, and other income allocated to DNI. Capital gains are treated differently:

• Capital gains typically stay in the trust. Most trust documents and state law allocate capital gains to principal, not accounting income. Gains are therefore not included in DNI and are generally not distributable without a principal distribution.
• Trust capital gains are taxed at compressed rates. Trusts hit the 20% long-term capital gains rate at approximately $16,250 of income (2026), compared to over $600,000 for a single individual.² Add the 3.8% NIIT, and retained long-term capital gains above that threshold face a combined federal rate of 23.8%.
• The post-death window is valuable. Immediately after death, many assets have a stepped-up cost basis (IRC § 1014), meaning capital gains are zero or minimal. The longer assets are held, the more gain accumulates — and the more that gain will eventually be taxed at trust rates if retained, or at beneficiary rates if distributed via a principal distribution.
• In-kind distributions may be better than cash. Distributing appreciated securities in-kind to beneficiaries carries out the gain at their rate and also gets the asset out of the trust's compressed bracket permanently. Model this with your CPA before realizing gains at the trust level.

When the distribution strategy is constrained

The calculator assumes discretion. Not all trustee situations have it:

• Mandatory income trusts (including many QTIP trusts, bypass trusts, and older revocable trusts) require the trustee to distribute all accounting income at least annually. You have no discretion to withhold — and the distribution deduction is automatic.
• HEMS restrictions limit principal distributions to health, education, maintenance, and support purposes. You cannot distribute principal to shift tax brackets if there is no qualifying HEMS reason.
• Multi-beneficiary impartiality complicates income-only trusts. If the trust has an income beneficiary (surviving spouse) and remainder beneficiaries (children), you must balance current income distribution against the trust's long-term growth. Systematically retaining all income may harm the income beneficiary; distributing everything may harm the remainder.

How a fee-only advisor helps

The math in this calculator is straightforward. The decision is not:

• Is distributing in the trust's best interest — or just the current income beneficiary's?
• Does the HEMS standard actually permit a principal distribution?
• Should the 65-day election be made, and by when must distributions be executed?
• Are there state income tax consequences that flip the analysis?
• Would an in-kind distribution of appreciated securities be better than a cash distribution?

A fee-only advisor with trust experience runs this analysis annually, coordinates with the CPA on Form 1041 reporting, and documents the decision process in writing — which matters if a beneficiary later challenges whether you managed the trust prudently.

1. IRC § 663(b) — 65-day election for complex trusts and estates (LII / Cornell)
2. IRS Rev. Proc. 2025-32 — 2026 inflation adjustments including trust brackets and capital gains thresholds
3. IRS Form 1041-ES (2026) — Estimated Income Tax for Estates and Trusts (confirms bracket thresholds)
4. IRS Topic 559 — Net Investment Income Tax (3.8% NIIT threshold for trusts at $16,000)

Tax values verified against 2026 sources. Trust ordinary income brackets: IRS Rev. Proc. 2025-32 ($3,300 / $11,700 / $16,000 thresholds). NIIT threshold: IRS Topic 559. Capital gains 20% threshold: approximately $16,250 per Rev. Proc. 2025-32.