In the United States, state law governs trusts. Trust law is therefore variable from state to state, though many states have adopted the Uniform Trust Code, and broad similarities exist among states' common law of trust as well. These similarities are summarized in the Restatements of the Law, such as the Restatement of Trusts, Third (2003−08). Additionally, as a practical matter, federal law considerations such as federal taxes administered by the Internal Revenue Service may affect the structure and creation of trusts.
In the United States the tax law allows trusts to be taxed as corporations, partnerships, or not at all depending on the circumstances, although trusts may be used for tax avoidance in certain situations. For example, the trust-preferred security is a hybrid (debt and equity) security with favorable tax treatment which is treated as regulatory capital on banks' balance sheets. The Dodd-Frank Wall Street Reform and Consumer Protection Act changed this somewhat by not allowing these assets to be a part of (large) banks' regulatory capital.
Living trusts, as opposed to testamentary (will) trusts, may help a trustor avoid probate. Avoiding probate may save costs and maintain privacy and living trusts have become very popular. Probate is potentially costly, and probate records are available to the public while distribution through a trust is private. Both living trusts and wills can also be used to plan for unforeseen circumstances such as incapacity or disability, by giving discretionary powers to the trustee or executor of the will.
Negative aspects of using a living trust as opposed to a will and probate include upfront legal expenses, the expense of trust administration, and a lack of certain safeguards. The cost of the trust may be 1% of the estate per year versus the one-time probate cost of 1 to 4% for probate, which applies whether or not there is a drafted will. Unlike trusts, wills must be signed by two to three witnesses, the number depending on the law of the jurisdiction in which the will is executed. Legal protections that apply to probate but do not automatically apply to trusts include provisions that protect the decedent's assets from mismanagement or embezzlement, such as requirements of bonding, insurance, and itemized accountings of probate assets.
Estate tax effect
Living trusts generally do not shelter assets from the U.S. federal estate tax. Married couples may, however, effectively double the estate tax exemption amount by setting up the trust with a formula clause.
For a living trust, the grantor may retain some level of control to the trust, such by appointment as protector under the trust instrument. Living trusts also, in practical terms, tend to be driven to large extent by tax considerations. If a living trust fails, the property will usually be held for the grantor/settlor on resulting trusts, which in some notable cases, has had high tax consequences.