This paper examines the optimal use of tax incentives relating to the Hawaii sales, use and excise tax. While many states offer exemptions to these taxes, Hawaii is the only known state that ties its excise tax credit to the depreciation method used on the state income tax return. Therefore, the purpose of this study is to use the Hawaii business tax context to illustrate the complex trade-offs and year-by-year analyses that small businesses often must employ in the presence of shifting federal tax policy that indirectly influences state tax structures because of tax coupling. Federal and Hawaii taxpayers can elect to expense depreciable property using the 179 expensing provision or to depreciate using the modified accelerated cost recovery system (MACRS). We develop a model that will help non-corporate small businesses in Hawaii determine their optimal tax cost recovery strategy: (1) Utilize Hawaii Section 179 immediate expensing on purchases of tangible personal property, or alternatively (2) Employ MACRS depreciation on these purchases combined with the Hawaii Capital Goods Excise Credit. Our modeling separately considers the possibility that the proprietor jointly makes the federal and Hawaii cost recovery decision, as well as the alternative possibility that these cost recovery decisions are made independently. The study illustrates that the interaction of federal and state law differences exacerbated by frequent tax changes may cause significant tax compliance complexity and resulting confusion for small non-corporate business taxpayers who are generally not equipped to wrestle with such issues. From a policy perspective, states may wish to minimize complexity using coupling efforts with federal law or otherwise routinely revisit outdated state tax statutes that indirectly cause unintended tax consequences. States must be cognizant, however, that their own budget constraints may worsen if they fully couple with recent generous federal Section 179 expensing limits.