A Credit Shelter Trust allows a married couple to minimize their estate taxes while still allowing the surviving spouse to have access to the entire estate.

The Credit Shelter Trust (CST) is also referred to as Bypass Trust or B Trust in an A-B Trust Plan. The CST is appropriate for clients who expect to face estate taxes, and is an alternative to using the unlimited marital deduction for all assets in order to reduce total estate taxes.

When using the unlimited marital deduction on all property of the first to die, the two estates are essentially merged into one larger estate that will be subject to estate tax at the second death. At the survivor’s death, his/her estate can claim his/her unified credit to offset a portion of the taxes.

The exemption equivalent in 2017 is $5.49 million. A couple can protect nearly $11 million from estate taxes using a CST in 2017. The exemption amount is indexed for inflation in future years.

In order to use both unified credits, estate assets can be left to non-spousal heirs at the first death as well as the second death. The disadvantage of leaving assets directly to non-spousal heirs at the first death is that the surviving spouse does not receive that money. Many people are uncomfortable with that and fear the spouse may someday need that money. The CST solves this dilemma.

Mechanics of a CST
The CST is funded with assets from the estate of the first to die. During the surviving spouse’s lifetime, he/she can receive income from the CST assets and, subject to certain limitations, even invade principal if needed. At the survivor’s death, trust assets are generally not included in the survivor’s estate, and are passed to the non-spousal heirs as outlined in the trust. Thus, the surviving spouse is not put at financial risk, and yet the trust assets are not counted as part of his/her estate.

The first to die typically puts an amount of assets into the CST equal to the exemption equivalent in the year of death. Any more assets than that, and estate taxes would be due although some planners recommend paying some taxes at the first death in order to avoid a higher estate tax marginal rate upon the death of the surviving spouse. By funding a CST with assets up to the exemption amount, the couple successfully uses both unified credits and minimizes total estate taxes.

A CST can only be funded with assets individually owned by the first to die. Therefore, each half of the married couple should own enough assets in his/her name to fund a CST upon death. If one person does not own enough assets to fully fund a CST, a retitling of specified assets is needed.