Estate tax rates at both the federal and state level are set by lawmakers, and there is little that any individual can do on thee law. However, residents can significantly alter their tax burden with smart estate planning–like prioritizing tax free transfers (to a spouse), using protected trusts, and more.
But there is also another aspect to the estate bill that is often overlooked–the appraisal. The tax burden is based on applying a tax rate to the value of an asset. But who decides the value? Actual laws which set the rates cannot account for this detail, and so disputes about appraisals are quite common, often with millions of dollars on the line.
Theoretically, the value of many different assets can be disputed. But in practical terms there are some types of property that are open to far more value uncertainty, often spurring challenge. Perhaps the most obvious example is that of high-end artwork. There may be significant disagreement about how much each piece of art is worth.