Implementing research-based curricula and instruction in inclusion-oriented schools is helped or hindered by having coherent models of service delivery accounting for the full range of student diversity. The current investigation offers data from 174 participants in 32 schools, analyzed using descriptive statistics, correlation, and hierarchical linear modeling (HLM). The findings offer replication of special education service delivery data from an earlier study, new descriptive data, and HLM analyses that identify special educator school density (the number of special educator full-time equivalents to total school population) and individual special educators' Individualized Education Program (IEP) caseload size as variables predictive of special educators' ratings of the conduciveness of their working conditions to providing effective special education for students on IEPs. (Contains 4 tables.)