Using data from the 2015-16 round of the Private School Universe Survey, I examine the types of private schools that decide to participate in school voucher programs in seven locations: Milwaukee, Wisconsin, Indiana, Ohio, Louisiana, D.C., and North Carolina. Regression analysis indicates that more specialized private schools tend to be less likely to participate in voucher programs than regular private schools. Specifically, the preferred model finds that private schools that identify as Montessori, special education, and alternative are less likely to participate in voucher programs than schools that identify as regular. In addition, schools that are non-coeducational and schools that focus on serving homeschool students are less likely to participate in voucher programs. I also find that random admissions mandates and state testing requirements are negatively associated with private school participation in voucher programs, while the prohibition of copayment is positively associated with program participation.