As an executor of an estate, which piece of information is least important when a client dies with assets in his own name?

The least important piece of information when a client dies with assets in his own name is the decedent's cost basis on assets. While understanding the cost basis is relevant for determining capital gains tax implications for the estate or beneficiaries, it is not as critical for the immediate administration of the estate itself.

The date of death value of the taxable estate is essential because it establishes the value of the assets for estate tax purposes. The date of death value of each asset is also crucial as it determines what the estate will be valued at from a tax perspective and helps in the distribution of assets among beneficiaries. The value of taxable gifts made is important for calculating how much of the estate is subject to taxes, as it can impact overall tax liability.

In contrast, while the cost basis can influence tax calculations later when beneficiaries sell the assets, it does not affect the estate's current valuation or the executor's responsibilities in executing the estate, thus making it the least critical piece of information in this context.