In my last post, I noted that readers should review their estate planning documents to determine if and how the sweeping new federal tax law impacts their planning. One likely effect that will require married readers to reconsider their estate plans is the common use of formula clauses in wills. A formula in a will is just what it sounds like: instructions relating to the disposition of the estate that are based on some particular formula.

But now, under the new law, this sort of thing in your will could be a formula for disaster?