Most estate planning conversations focus on the legal structures: which trusts to create, how to draft the documents, who the trustees should be. The investment conversation — what actually goes into the trust, and how it should be managed once it is there — often happens later, sometimes much later, and sometimes not at all.
This is a significant gap. Funding a trust is not just a legal exercise; it is an investment event with real consequences for taxes, portfolio construction, and long-term performance. Understanding those consequences can help you evaluate potential tax and portfolio-construction implications before implementation rather than discovering them afterward.
What "Funding a Trust" Actually Means
A trust is a legal entity. When you create one, you have created a container — but until assets are transferred into the trust, it generally cannot carry out the purposes for which it was established. Funding is the act of moving assets: transferring brokerage accounts, retitling real estate, assigning business interests, or otherwise placing assets under the trust's ownership. For a revocable living trust, funding is relatively simple and not a taxable event. For an irrevocable trust, the analysis is more complex.
Choosing Which Assets to Put Into a Trust
Not all assets are equally well-suited for irrevocable trust funding. The selection requires coordination between your estate attorney and your wealth advisor.
Assets well-suited for irrevocable trust funding
- High-growth assets with low current values. GRATs and similar vehicles work best with assets expected to appreciate significantly. Contributing a business interest or concentrated stock at today's lower value means future appreciation passes outside the grantor's taxable estate, subject to the trust terms, valuation rules, and applicable tax law.
- Assets with significant valuation discounts. Minority interests in family limited partnerships or LLCs may qualify for valuation discounts, reducing the taxable value of what is contributed, subject to applicable valuation rules and IRS scrutiny.
- Assets with low embedded capital gains. Contributing an asset to an irrevocable trust generally does not itself trigger a capital gain, and the trust generally takes a carryover basis, subject to the trust structure and applicable tax rules. Assets that won't need to be sold anytime soon are generally better candidates than highly liquid positions you'll need to sell to fund distributions.
The step-up in basis question is critical. Assets that move into an irrevocable trust may not receive the step-up in basis at death if they are excluded from the grantor's gross estate. For highly appreciated assets intended to be held long-term, keeping them in your personal estate may be preferable after weighing estate-tax exposure, basis-step-up treatment, and other relevant factors, even if it means they remain in your taxable estate.
Assets generally not suitable for irrevocable trust funding
- Retirement accounts (IRAs, 401(k)s). These generally cannot be retitled into a trust without potentially adverse income-tax consequences. Beneficiary-designation planning may be an alternative, depending on the account, trust terms, and applicable law.
- Highly appreciated assets you plan to hold indefinitely. If the step-up in basis at death is the goal, keeping these in the personal estate may be worth considering, subject to estate-tax, liquidity, and control considerations.
How Trust Assets Are Managed Differently
The trustee has a fiduciary duty
The trustee has a legal fiduciary duty to manage trust assets prudently under the Uniform Prudent Investor Act and the terms of the trust document. This means the trustee is responsible for investment decisions — not the grantor. If you are the grantor of an irrevocable trust and also the trustee, specific legal constraints apply.
Income tax treatment may differ significantly
For non-grantor trusts, the trust reaches the highest federal income tax brackets at a much lower income level than an individual taxpayer. As of 2026, a trust reaches the 37% bracket at approximately $16,550 of taxable income (adjusted annually for inflation; IRC §1(e), Rev. Proc. 2025-22). This compresses the tax efficiency of income-producing investments held inside the trust and should be factored into asset selection and portfolio design.
Investment policy should reflect the trust's specific purpose
A trust created to benefit grandchildren 40 years from now has a very different investment horizon and risk tolerance than a trust designed to provide income to a surviving spouse in retirement. The investment policy for trust assets should be tailored to the trust's specific beneficiaries, distribution standards, and time horizon — not simply replicated from the grantor's personal portfolio.
| Asset Type | In Personal Account | In Irrevocable Trust |
|---|---|---|
| Step-up in basis at death | Yes — basis resets to FMV | No — basis carries over |
| Income tax rates | Individual brackets apply | Compressed (37% at ~$15K income) |
| Estate tax inclusion | Yes — in taxable estate | No — removed from estate |
| Creditor protection | Limited | Strong (discretionary trusts) |
| Retirement accounts | Held, beneficiary-designated | Cannot transfer without tax event |
The Coordination Required
The investment analysis described here does not happen automatically when an estate attorney creates a trust. It requires active coordination between the estate attorney (who designs the structure), the CPA (who understands the tax consequences of different assets in the trust), and the wealth advisor (who manages the portfolio and can model the implications of different funding decisions). When this coordination happens proactively — before the trust is funded — families make better decisions about which assets to contribute and how to structure the portfolio inside the trust for its actual purpose.