The Supreme Court waited until the last day of the 2009-10 Term to issue its pronouncement on business method patents, Bilski v. Kappos. It then came “not with a bang but a whimper.” Those who thought, based on statements in earlier Court opinions or the tenor of oral argument in Bilski, that the Court might find all business methods, including tax strategies, not to be patentable subject matter, were disappointed. All the Justices agreed that patent protection did not extend to Bilksi's hedging strategy process claims because they involved only an abstract idea. All agreed as well that the Federal Circuit's machine-or-transformation test was not the sole test for patentability of a process, although they recognized that it was an important and useful test in many, perhaps even most, cases. They also declined to endorse the Federal Circuit's prior test for patentability, whether the invention produced a “useful, concrete and tangible result.” The five members of the majority, in an opinion by Justice Kennedy, read the patent law as leaving open “the possibility of some business method patents.” At the same time, the opinion was quick to disclaim “broad patentability of such claimed inventions.” But the majority failed to offer guidance on when an idea is an abstract idea or what the limits on business method patents might be. After Bilski, the status of patents on tax strategies, as one type of business method patent, is no clearer than it was before the case was decided. Under the machine-or-transformation test, applications for tax strategy inventions that did not depend on computer software were clearly not patentable. Although it will depend on how the Patent and Trademark Office, lower courts, and the Federal Circuit analyze and apply the term “abstract idea,” the same result is likely, but not certain, to hold after Bilski. Tax strategy patents may provide a rich testing ground for determining whether it is possible for an invention that does not meet the machine-or-transformation test nonetheless to be patent eligible because it is a practical application of an abstract idea. Some further guidance maybe available when the Federal Circuit decides Fort Properties, Inc., which involves section 1031 like-kind exchanges. Both before and after Bilski, another set of issues involves tax applications for tax strategies with claims that include use of computers or computer software, which many tax strategy patents already, or easily could, do. The PTO has issued thoughtful Interim Bilski Guidance, but difficult questions remain when this guidance is applied to tax strategy patents. For those who believe that, as a matter of policy and practice, tax strategies should not be patented, Bilski underscores the need for legislation, although drafting and passing such legislation involve a number of challenges. This article provides background on business method patents generally, on tax strategy patents in particular, and on the Bilski case before discussing the Supreme Court opinion, its implications for business method patents, and its implications for tax strategy patents.