For many years, increasing caseloads for vision professionals have caused concerns about the impact on educational services. Average caseload sizes in the literature have remained fairly consistent across decades, with 19.5 students per professional in the 1980s (Pelton, 1986), 18 students in the 1990s (Griffin-Shirley, McGregor, and Jacobson, 1999), and 22 students in the 2000s (Griffin-Shirley et al., 2004). In contrast, the optimal caseload for vision professionals has been approximated as eight students (Mason & Davidson, 2000). Goal 4 of the National Agenda for the Education of Children and Youths with Visual Impairments, Including Those with Multiple Disabilities noted that caseloads are based on the assessed needs of students (American Foundation for the Blind, 2003). An example of such a rubric for determining service delivery levels was developed by the Atlantic Provinces Special Education Authority (see, for example, MacCuspie, 1998). In 1995, the Michigan Department of Education's Low Incidence Outreach office began adapting a model developed in Montgomery County, Pennsylvania, that used student and environmental characteristics to determine service delivery levels. The task force that was created to adapt the model developed a set of "in house" severity rating scales to determine optimal vision service levels. The scales were revised in 2008 based on feedback from surveys of Michigan vision professionals and with input from professionals across the United States. The scales are now popular enough that national surveys of how the scales are being used seemed appropriate. They are available online at the Low Incidence Outreach website: http:// mde-lio.cenmi.org/Services/StudentsWitha VisualImpairment/MichiganSeverityRating Scales.aspx. The current study reports on the responses from a cross section of orientation and mobility (O&M) instructors and teachers of children with visual impairments to demonstrate how the scales are perceived and being used by professionals. The study presented here also reflects an initial attempt at determining content validity of the scales. The four severity rating scales assessed were the Orientation and Mobility Severity Rating Scale (OMSRS); the Orientation and Mobility Severity Rating Scale Plus (OMSRS), which is for use with children with multiple disabilities; the Vision Services Severity Rating Scale (VSSRS); and the Vision Services Severity Rating Scale Plus (VSSRS), which is for use with children with multiple disabilities.