This study was designed to investigate Iowa's funding mechanism for special education instructional programs, the "Weighting Plan" which has been in effect since the 1975-76 school year. An operational explanation of the "Weighting Plan" is presented and includes its relationship to Iowa's overall public school finance plan, procedures for the classification of handicapped students, and the role of the School Budget Review Committee. The "Weighting Plan" is also described in standardized terminology suggested by Timothy Crowner and is evaluated based on criteria found in the literature, including; equity, comprehensiveness, compatibility with the total educational finance system, congruency with state educational policies, and lack of complexity;Pupil and finance data are presented and analyzed from 1975-76 through 1983-84. This data includes comparison with regular and special education instructional enrollments and budgets. Findings include: (1) unduplicated, certified special education instructional enrollments increased by 22.53 percent while public enrollments declined by 21.24 percent from 1975-76 through 1983-84; (2) the percentage of the total instructional budget devoted to special education increased from 8.48 percent of the total to 14.70 percent; and (3) deflated regular program budgets declined 13.91 percent while special education budgets increased 52.2 percent over the nine year period;The author suggests that Iowa's special education program delivery system needs further study. Differences in identification, weighting, and placement procedures between geographic and administrative regions of the state as defined by the boundaries of the intermediate education agencies should be investigated. If significant differences are found, their impact on the finance component of the program delivery system should be assessed. Alternative methods to deliver instructional services to mildly handicapped and "borderline" students also requires additional study may lead to a more cost-effective funding mechanism.