Throughout the history of publicly-funded voucher programs--enacted and proposed--the impact on taxpayers has been a recurring issue. As the nation's longest-running program, the Milwaukee Parental Choice Program (MPCP) provides an important case study. The fiscal impact of Milwaukee's program has evolved in very significant ways over its 18-year history, both in size (as the program grew) and in its allocation among different groups of taxpayers--Milwaukee property taxpayers, non-Milwaukee property taxpayers, and Wisconsin state taxpayers. This report closely examines the features of the MPCP funding formula, and its interaction with the state's regular district funding formula over the program's history to better understand the impact on taxpayers. Appendices include: (1) Review of selected previous literature; (2) Further Details in Funding Formulas; and (3) Equations Underlying Tables and Figures. (Contains 66 footnotes, 8 tables, and 9 figures.)